On Christmas Day, Jade Sharpe watched as her 13-year-old daughter Kennedi Chandler took her brand-new e-bike – capable of going about 20 mph – for a spin in their Indiana neighborhood.

Her parents had a plan to get Kennedi a key piece of safety gear. But they didn’t have the heart to say no when, on the unseasonably warm holiday, she asked to ride the electric bike she’d begged them for – without a helmet.

Less than two hours later, the teenager hit the pavement.

“The next thing I knew was flashing lights, and then just … heart sunk. You just know,” Sharpe told CNN.

“I didn’t realize how bad it was until we were in the ambulance,” Sharpe said. Even though they live in a big suburb of the state’s biggest city, they weren’t heading to the closest hospital. “And then you realize we’re going to the best trauma center Indianapolis has, and that’s because that’s what she needed.”

Kennedi sustained a traumatic brain injury and spent the next 20 days in the hospital, 14 in intensive care. Doctors had to remove part of her skull to quell the swelling and bleeding in her brain.

“This surgeon,” Sharpe said, “has expressed how many bicycle accidents she’s had come through over the years, and Kennedi is lucky – so very lucky.”

But these aren’t your mother’s manual bicycles. Their colors are sleeker. Their tires are bigger. And, most importantly, they’re outfitted with motors that can power them to speeds exceeding 30 mph.

Several cases this year in California highlight the risks: In Fresno, a 13-year-old died and two other children were seriously injured in two separate e-bike crashes, police said. In Garden Grove, a 13-year-old boy died after approaching a curve at around 35 mph and colliding with a center median while riding what authorities said was an electric motorcycle. And in Lake Forest, a 14-year-old doing wheelies on an e-motorcycle – able to reach 56 mph – struck and killed an 81-year-old Vietnam veteran walking home from his job as a substitute teacher, the Orange County District Attorney’s Office said.

The Lake Forest boy’s mother – who prosecutors say was previously warned it was illegal for her son to ride the e-motorcycle – now faces an involuntary manslaughter charge. Meanwhile, the Orange County district attorney has filed child endangerment charges against three parents this year for allowing children to ride electric motorcycles illegally, calling the devices “deadly weapons.”

As gas prices rise, many in the cycling community have praised e-bikes as an eco-friendly and active alternative to other forms of transportation. But the spate of recent crashes involving children and teens – some riding high-powered motor vehicles they are not legally allowed to use – has prompted moves toward more regulation on the roads, transparency among sellers and a closer look by parents at what their children are really riding.

Atlanta emergency room physician, Dr. Darria Long, has become all too familiar with e-bike-related injuries in the last five to 10 years – including head injuries, fractures, concussions, chest injuries, cardiac arrest and even death.

Families who didn’t realize the power of the bikes or motor vehicles their children were riding were often surprised to find themselves in an emergency room, the doctor said.

“They thought their kid was just doing something fun. They thought that by giving them a helmet, maybe they prevented all injuries – and then they’re devastated, because every parent loves their child, and they don’t want to see their child being injured. And they didn’t know,” she said.

Following her late-December injury and weeks of missing school, Kennedi is now finishing her last round of occupational, physical and speech therapy. She’s playing soccer again and is excited to get back on a bike – this time, her mom said, with a helmet.

“It could be so much worse than what you think,” Sharpe said. “It’s not just a broken bone.”

Between 2017 and 2024, the US Consumer Product Safety Commission documented 533 micromobility fatalities – a category that includes e-bikes, e-scooters and other small electric vehicles – rising from five in 2017 to 135 in 2024. Emergency department visits quadrupled in the same period, from 37,300 to 149,100, according to the commission’s report, published in April. E-bike deaths alone rose from zero in 2017 to 97 in 2024.

That doesn’t include motorized vehicles like mopeds or e-motorcycles that exceed e-bike limits and fall outside the commission’s scope but are often grouped under the e-bike umbrella in consumer consciousness and retail descriptions. As a result, some deadly crashes involving young riders aren’t included in the count.

Children between the ages of 11 and 14 accounted for 61.7% of e-bike and e-motorcycle crashes, and injuries have spiked 430% in the last four years in Southern California alone, data cited by the Orange County District Attorney’s Office show.

The first factor is where these bikes are being ridden: often on public streets, alongside cars – some at speeds comparable to those of cars, Long said.

“There is no minor bicyclist-versus-vehicle hit when you’re on public streets,” Long said. “A bicyclist on an e-bike – they’re not going to win that battle versus a car.”

And a helmet can only do so much.

“Yes, the helmet is making you safer than if you don’t wear the helmet, but at these speeds that we’re seeing, the trauma can be so bad that it can overcome the helmet,” the ER doctor said. “A helmet’s not going to help you if the car is going 40 miles an hour and you’re going 30.”

While Kennedi understands what happened to her, she doesn’t remember the details of the crash itself or the trauma of this past Christmas, her mom said.

“I’m glad we can hold that burden, that weight, for her,” Sharpe said.

For anxious parents who want to keep their own kids safe, Long has some advice: Never let children ride e-bikes on public streets; avoid modifications – bikes are sold with speed limits for a reason, and; outfit kids in full protective gear, including a motorcycle helmet and leather covering arms and legs.

“Effectively, these are mini motorcycles,” Long said. “The gear is not going to protect them in the biggest crashes, but it’s at least going to kind of give them a leg up.”

Last week, Amazon announced it would halt sales of e-bikes in California that exceed state limits, requiring third-party sellers to comply with California law and removing noncompliant listings. The Orange County district attorney, Todd Spitzer, announced it as a win in his crackdown on parents who let their children illegally ride e-motorcycles or modified e-bikes.

But, Spitzer said, the move came only after a local television station contacted Amazon about the sales – not after California’s attorney general issued a consumer alert in April, not after children had already died.

CNN has reached out to Amazon for comment.

AG Rob Bonta warned consumers e-bikes cannot exceed 20 to 28 mph in California, depending on type. Some that do are considered motorcycles or mopeds, requiring a DMV license and a minimum age of 16 to operate, though they are being marketed and sold by some retailers as e-bikes.

“We are seeing a surge of safety incidents on our sidewalks, parks, and streets,” Bonta said.

There’s an important distinction between electric bicycles and electric motorcycles, said Matt Moore, general counsel for People for Bikes, a national cycling coalition.

“Electric bicycles have been heavily regulated for over 20 years. They are consumer products. They are subject to (Consumer Product Safety Commission) safety regulations, recalls and they’re defined in federal and state laws everywhere,” Moore said.

Motorized bicycles that exceed certain speeds and mopeds are placed into a different classification by most states, with age and licensing requirements. But those distinctions haven’t broken through to consumers, many who seek out electric bicycles and going home with electric motorcycles, Moore said.

The confusion isn’t limited to consumers. “We have a lot of officers who really can’t tell the difference between an e-bike and an e-motorcycle,” Huntington Beach, California, Police Sgt. Mike Thomas said at a statewide e-bike safety symposium this week. “So, how is a parent going to be able to tell the difference?”

“Some of the online sellers are kind of perpetuating the confusion. They don’t tell you what you’re buying, or they claim that it’s a street-legal product,” Moore told CNN. “They will even claim that it’s a type of electric bicycle if it has a lower speed setting on the controller – so you can limit this device to 20 miles per hour, but you can also go 65 miles per hour – and they sell that as street legal.”

“There are no safety standards for these electric motorcycles that are being sold. They’re not tested. The batteries aren’t tested to these safety standards, and they’re just inherently dangerous,” he added.

The unwitting consumers are generally parents, given the price point – $1,500 to $3,000 – Moore said.

Then, there are the illegal modifications people can make at home, which can transform an e-bike into an e-motorcycle while making the difference almost indistinguishable. How-to videos are readily available online.

“You can’t give a child a gun, alcohol or anything else like that, but you can give them an illegal motorcycle,” Moore said. “It just makes no sense.”

When Georgia mom Krysten McCabe went for a walk through her Marietta neighborhood this past Christmas, she noticed a wave of excited children testing out brand-new bikes. At first, they looked like the bicycles she’d grown up riding.

One was barreling down the sidewalk, heading straight for McCabe – topped with a wobbly 10-year-old boy who appeared to be making no attempt to slow down. She grabbed her dog’s leash and got herself and her pet off the sidewalk before the boy could hit them.

She turned to warn the boy about how powerful his bike was, but he was soon on his way.

Scenes of e-bike “takeovers” – city streets suddenly filled with masses of teenagers riding in unison – have left bystanders rattled, drivers complaining about dangerous interruptions, and concerned parents flocking to community meetings and Facebook groups.

Some policy makers are catching on.

In Fishers, Indiana, where Kennedi crashed her bike on Christmas Day, the police department warned of an uptick in reckless riding and misuse of e-bikes and e-motorcycles, and a local ordinance was proposed that would require riders to be at least 15 years old with a valid ID to use them on roadways.

Now, as crashes mount, many question who should be held accountable – the parents who purchase e-bikes, the sellers who label them, the lawmakers who allow them on the roads?

People for Bikes’ Moore says the conversation is worthwhile. He likened the moment to the emergence several years ago of e-cigarettes and vape products among teenagers. Tobacco products were marketed to youth, sold in fruity flavors with colorful packaging.

“Youth became addicted, and attorneys general stepped in, they sued the companies that were selling the products and made them change their marketing,” Moore said. “That is exactly what should happen here. They need to stop selling motorcycles to kids as if they’re safe and appropriate – or even legal – to use.”

Last week, Spitzer announced the formation of a dedicated e-bike and e-motorcycle prosecution unit to review potential criminal charges against juveniles and adults, including parents who knowingly allow their children to ride illegal e-motorcycles.

In New Jersey, lawmakers in January passed what some have described as the most restrictive e-bike law in the country, narrowing the definition of a low-speed electric bicycle – one that maxes out at 20 mph – and treating all other e-bikes as motorized bicycles, with licensing and registration requirements.

Bike enthusiasts criticized the law as too restrictive and said it overlooks necessary regulations for e-motorcycles. They’ve also raised concerns that local restrictions and age limits on e-bikes around the country cast too wide a net, hurting bike-friendly communities in the attempt to protect children.

Meanwhile, some schools around the country are moving to ban e-bikes on and around campuses.

In Bradford, Pennsylvania, Police Chief Michael Ward recently warned against the dangers of high-powered e-bikes that can reach high speeds after a video of an e-bike rider colliding with and flipping over a car went viral. Police in Keller, Texas, issued a similar warning, along with dashcam video of young riders they said fled officers on streets. Such warnings have been echoed by police departments across the country dealing with chaotic riders and concerned parents.

Moore says his organization has worked to pass legislation in Minnesota, Utah, Colorado, Connecticut and California to prohibit retailers from advertising high-speed motorized vehicles as e-bikes. He’s hopeful halting some e-motorcycle sales in California – and similar moves – will create momentum toward regulation in other states.

But for now, in many cities, a parent can buy a vehicle capable of 60 mph, hand it to a child, and never be told it isn’t a bicycle.