SAN DIEGO -- A drone on patrol for U.S. Customs and Protection made an "emergency landing" in the ocean 20 miles southwest of San Diego after experiencing a mechanical problem, officials said Tuesday.
The craft has been brought back to San Diego by ship and is no longer a hazard to navigation, the Coast Guard said.
The incident occurred about 11:15 p.m. Monday when operators determined that the unmanned Predator B drone "would be unable to return" Sierra Vista, Ariz., where it originated, according to a statement from Customs and Border Protection.
The cause of the mechanical problem has not been determined, but Customs and Border Protection has grounded its drone fleet "out of an abundance of caution."
The Predator B was being used in a routine search for smugglers who might be heading for the coast of Southern California to unload drugs or undocumented migrants.
The landing was controlled by the drone operators, the agency said. There were no injuries. The drone broke apart upon impact.
The Predator B is a variant of the Predator A used by the U.S. and British to fly combat missions over Afghanistan. Able to fly in all weather conditions, the Predator B has a cruising speed of 150 to 170 knots.