MONTEREY, Calif. (AP) — Authorities reported that three individuals were discovered unresponsive on Sunday morning after a small plane went down in the Pacific Ocean near the central coast of California.

According to the U.S. Coast Guard, emergency personnel rushed to the scene late Saturday night after receiving reports of an aircraft crashing approximately 300 yards (275 meters) off Point Pinos in Monterey County.

Bystanders said they heard the airplane’s engine accelerate followed by a splash in the sea, as noted by KSBW-TV. People on the shore later observed wreckage from the airplane drifting to the beach.

The twin-engine Beech 95-B55 Baron with three people aboard took off from the San Carlos airport at 10:11 p.m. and was last seen at 10:37 p.m. near Monterey, according to flight tracking data from FlightAware.com.

Coast Guard boat and helicopter crews were launched to search for the victims, with assistance from local law enforcement and fire agencies.

Searchers in a boat found one person around 3 a.m. Divers found the remaining two people inside the aircraft between 6:30 a.m. and 9:15 a.m. All three were unresponsive, the Coast Guard said.

“In this case unresponsive means no signs of life, however it is the coroner’s office and Sheriff’s office that make the distinction of dead/deceased,” Petty Officer Ryan Graves said in an email. Messages were sent to the coroner’s office seeking more information.

The Federal Aviation Administration and the National Transportation Safety Board will investigate.