BUFFALO, N.Y. -- Starting with broken glass, police pieced together how a drone crashed through a window last week on the 23rd floor of Buffalo City Hall.

It belonged to a 19-year old Rochester man, who was apologetic when contacted by police. He was given his drone back and plans to pay the $500 to fix the window.

While police believe the crash, which happened in the evening hours was accidental, the Federal Aviation Administration is investigating. Drone experts speculate the crash could have been pilot error or a problem with the aircraft's GPS.

"When you take a building as big as Buffalo City Hall, it can actually block the GPS signal and if they don't have good flying skills, they can lose control and crash into a window," said Brian Pitre, SkyOp co-founder.

Police say the pilot was flying the drone for fun, and according to Pitre, that means he only needed to register the aircraft with the FAA and doesn't need a license.