Approximately 140 people died yesterday in one of the worst aviation disasters in United States history. A Pacific Southwest Airlines 727 carrying 133 people collided with a Cessana 150 flown by a student pilot on the approach to San Diego airport. At least three people died after the planes landed because their wreckage set several buildings on fire.

The student pilot of the Cessana apparently attempted an instrument landing in San Diego's Lindbergh Field. The collision occurred about 30,000 feet above the ground.

A Federal Aviation Administration official said yesterday both pilots received warnings that they were on a collision course and both acknowledged the warning.

Lt. Geroge Farrell a Navy flight surgeon who witnessed the accident, said yesterday, "They hit head on, it was unbelievable. The 727 went into a graveyard spin with the other plane trailing after it."

The crash occurred over a residential area of San Diego, and at least nine homes were damaged or destroyed in the airliner's fall.

Police and firemen cordoned off the area of the crash, but a crowd of 4000 to 5000 jammed the site of the disaster. The crash was the first fatal accident in the history of Pacific Southwest Airlines, an intrastate carrier that makes 200 flights a day within California.

The worst previous U.S. airplane disaster occurred in 1960 when 134 people were killed in a mid-air collision over New York City.