Authorities say three people were hurt when a U.S. Customs and Border Protection helicopter made an emergency landing on California's San Onofre State Beach.

U.S. Customs and Border Protection spokesman Vincent Bond says the McDonnell Douglas 600 helicopter had taken off from Long Beach Airport en route to Brown Field airport in San Diego on Thursday when the pilot experienced engine trouble.

The pilot brought the chopper down on the beach near the San Onofre nuclear power plant.

Bond says the three crew members on board, all U.S. Customs and Border Protection employees, were hospitalized with non life-threatening injuries. The helicopter suffered significant damage.

The helicopter was on a routine patrol mission at the time. The National Transportation Safety Board has been notified and will investigate.