Investigators trying to learn what sent an Alaska Airlines jet with 88 people aboard plunging into the Pacific Ocean had at least one clue today: the pilot sought an emergency landing after reporting problems with equipment designed to keep the plane aloft.

No survivors had been found by this morning. Several bodies were recovered from the 58-degree water, Coast Guard Lt. Chuck Diorio said, but he could not give a specific number. 

The Coast Guard and commercial squid boats continued to search the debris field 10 miles from shore in water from 300 feet to 750 feet deep. As the stench of airline fuel hung in the air, the boats used nets to haul in grim reminders of lives lost: a tennis shoe, a stuffed animal and a number of small souvenirs from Mexico. 

"Every resource is out there to find people," Coast Guard Capt. George Wright said. "We're actively searching for survivors." 

Flight 261 from Puerto Vallarta, Mexico, to San Francisco and Seattle hit the water 40 miles northwest of Los Angeles International Airport at 4:36 p.m. Monday. The weather was clear at the time. 

Moments before the crash — described by a witness as a nose dive — one of the two pilots radioed that he was having trouble with "stabilizer trim" and asked to be diverted to Los Angeles for an emergency landing, airline spokesman Jack Evans said. 

"Radar indicates it fell from 17,000 feet and then was lost from radar," San Francisco airport spokesman Ron Wilson told KRON-TV. 

The flight was normal and stable until the crew reported control problems, said a source with close knowledge of the investigation, speaking on condition of anonymity. Radar showed the plane, an MD-83, plummeting toward the sea shortly afterward. 

On MD-80 series airplanes, the horizontal stabilizer looks like a small wing mounted on top of the tail. The stabilizer, which includes panels that pitch the nose up and down, is brought into balance, or "trimmed," from the cockpit. 

If a plane loses its horizontal stabilizer, there is no way to keep the nose pointed to the proper angle, and the aircraft will begin an uncontrollable dive. 

Evans said the plane had no previous stabilizer problems, and Federal Aviation Administration spokesman John Clabes said it had never been in an accident. 

National Transportation Safety Board investigators were expected to be on hand by tonight. 

"We will do anything and everything to find out exactly what transpired," airline Chairman John Kelly said late Monday. 

A National Park Service ranger on Anacapa Island, off the coast of Oxnard, saw the airliner go down and was first to report it, said spokeswoman Susan Smith at the Channel Islands National Park headquarters in Ventura Harbor. 

"He observed a jet going down in the Santa Barbara Channel. From his observation it was nose first," Smith said. 

There were 83 passengers and five crew members aboard, Evans said. 

Of the passengers, 32 were bound for San Francisco, 47 for Seattle, three were continuing on to Eugene, Ore., and one to Fairbanks, Alaska. The two pilots were based in Los Angeles and the three flight attendants were based in Seattle. 

The passengers included three airline employees, four employees of sister airline Horizon and 23 relatives or friends of the employees. 

Both pilots were Alaska Airlines veterans. Capt. Ted Thompson, 53, was hired Aug. 16, 1982, and had 10,400 flying hours with the company. First Officer William Tansky, 57, was hired July 17, 1985, and had 8,047 flying hours with the Seattle-based airline. 

The plane itself was built by McDonnell Douglas, now part of Boeing, and delivered to Alaska Airlines in 1992, said John Thom, a spokesman for Boeing's Douglas aircraft unit. 

Evans said the plane was serviced on Sunday, went through a low-level maintenance check on Jan. 11 and had a more thorough routine check last January. 

Alaska Airlines, which has the image of an Eskimo painted on the tails of its planes, has an excellent safety record. It serves more than 40 cities in Alaska, Canada, Mexico and five Western states. 

It had two fatal accidents in the 1970s, both in Alaska. 

The MD-80 series is a twin-jet version of the more widely known DC-9, with a single aisle and an engine on each side of the tail. It went into service in 1980 and of the 1,167 series planes delivered, Boeing reported last year, only nine had been lost in accidents. 

Before this week, the most recent fatal crash in the United States involving an MD-80 series jet was last summer's American Airlines accident in Little Rock, Ark. Eleven people died and 110 were injured when an MD-82 trying to land in a storm ran off a runway, broke apart and caught fire.