A United Airlines flight and a drone may have struck each other prior to the flight's arrival in Southern California, the airline said on Wednesday, April 29.

United Airlines said in a statement to the USA TODAY Network that United flight 1980 “reported a possible drone strike” prior to it arriving in San Diego.

United Airlines did not respond to questions about the time and date of this flight. However, flight tracking data from FlightAware shows that United flight 1980 departed from the San Francisco International Airport at 6:53 a.m. on April 29.

The crew of the flight told air traffic control that they believed they saw a drone 1,000 feet below them while approaching the San Diego International Airport at about 4,000 feet altitude, according to a Federal Aviation Administration statement.

“Air traffic control alerted other pilots but did not receive any additional drone-sighting reports,” the FAA said.