CALIFORNIA NEWS : Plane Wreckage, 4 Bodies Found at Camp Pendleton : Tragedy: Two of the dead were physicians at UC Irvine. The aircraft apparently hit a ridge and crashed into a canyon on a medical mission to Mexico.

Four bodies and the scattered wreckage of a small civilian airplane were discovered in a remote Camp Pendleton canyon Monday, three days after the craft disappeared minutes after takeoff from John Wayne Airport on a medical mission to Mexico.

The twin-engine Piper Apache 23, carrying two physicians from the UC Irvine Medical Center, left Orange County in fog and dense clouds and lost radio contact 17 minutes later, when officials believe it slammed into the side of a 1,000-foot-deep canyon a few miles southeast of the Border Patrol checkpoint on Interstate 5.

“It looks like they hit the north side of the ridgeline, lost a wing and cartwheeled over,” said Robert Praytor, the fire chief at the Camp Pendleton Marine base.

The plane’s nose, engine and wing were torn off. One body was found in the remains of the fuselage, the other three outside the wreckage.

UC Irvine Medical Center spokeswoman Fran Tardiff identified the physicians as Dr. Francis Markoe Dugan Jr., a 37-year-old father of two from Santa Ana, and Dr. George Brauel, 34, of Fountain Valley. Dugan was assistant clinical professor of head and neck surgery and Brauel was chief resident in that department.

The other two victims, both pilots, were Anthony Shanks and Randy V. Breding, both of Sacramento, said a spokesman from LIGA International Inc. The company, better known as the Flying Doctors of Mercy, had arranged the flight as part of an 800-mile medical mission involving 15 planes headed to Los Mochis, in the Mexican state of Sinaloa.

A San Diego County Sheriff’s Department helicopter discovered the wreckage about 11:20 a.m. Monday. A rescue crew from the Marine Corps base at El Toro rappelled down the cliff and rigged up pulleys and hoists to remove the bodies.

Praytor said the plane crashed about a mile east of Interstate 5 and two miles north of Las Pulgas Road after leaving John Wayne Airport at 9:20 a.m. Friday. Although visibility was limited because of poor weather conditions, it is too early to tell if weather contributed to the crash, a National Transportation Safety Board investigator said.