Amazon has paused drone deliveries in the West Valley Phoenix Metro Area after a pair of its MK30 drones crashed into a crane. The crash happened on Wednesday morning at around 10AM local time in Tolleson, Arizona, approximately two miles from an Amazon distribution center where the drones launch and land. There were no injuries reported, but according to a report by ABC15 Arizona news in Phoenix, one man was treated for smoke inhalation from the wreckage.

Gabriel Dahlberg, a diesel mechanic who witnessed one of the crashes from a nearby lot while parking a truck, told KPNX’s 12 News that the drone clipped the cable of the crane that was being used to lift equipment onto a building. According to Sergeant Erik Mendez of the Tolleson Police Department, the preliminary investigation showed that the two Amazon drones were flying back to back when both crashed into the crane and landed approximately 100 to 200 feet apart in separate parking lots.

Local fire and police departments responded to the incident, but the Federal Aviation Administration (FAA) says it will investigate the incident with Amazon’s cooperation. “We’re aware of an incident involving two Prime Air drones in Tolleson, Arizona. We’re currently working with the relevant authorities to investigate,” Amazon spokesperson Terrence Clark told The Verge in an emailed statement.

Amazon began same-day drone deliveries in Tolleson last November using its MK30 drones that can carry payloads up to five pounds. It’s not known how long the service will be paused, but it’s the second time the drones have been grounded in the area since beginning operations less than a year ago. Last January drone deliveries were paused so Amazon could complete software updates and FAA validations following a drone crash at a testing facility in Oregon.