Seattle police are investigating after a drone collided with the city's giant Ferris wheel on Wednesday afternoon.
There were no injuries in the incident in which the drone hit the wheel and then a table as it fell to the ground.
The incident has added weight to calls to introduce national registers for the unmanned aerial vehicles (UAV).
The US has started up a register while the Irish Aviation Authority (IAA) has just announced similar plans for UAVs weighing over 1kg.
The area on Seattle's Pier 57 is understood to be a no-fly zone.
Drone or unmanned aerial vehicle (UAVs) usage is skyrocketing with the Federal Aviation Administration estimating that by 2020 in the US there will be approximately 30,000 commercial drones in use and many more civilian devices.
Last month the US Department of Transportation and the FAA announced that they were preparing a registration scheme that would allow them to "track down people who fly drones above the FAA designated-altitudes, or get too close to airports and other restricted zones".
In Ireland, from 21 December, all drones weighing over 1kg must be registered while in the UK the House of Lords EU Committee have called for the compulsory registration of all commercial and civilian drones.
Drone crashes are increasingly hitting the headlines:
- In September a drone slammed into the seating area at the US Open tennis tournament
- In July a woman was hit on the head when a drone fell on her at a gay pride parade in Seattle
- In April 2014 an Australian triathlete was injured during a race
- A drone used in the TGI restaurant in New York to carry mistletoe among diners cut a woman's face in December 2014
Drone use has raised privacy and security questions too. When a quadcopter drone crashed into the White House lawn in January, it caused minor panic until it emerged that the operator was a government employee.
As the number of drone-related accidents increases, so drone liability has emerged as a field of law and drone injury lawyers are setting up websites to help people who have been "injured by drone".