Witnesses said Shawn, 57, was left lying on the stage for nearly five minutes before the audience realized it was not part of his act, and an ambulance was called. Hospital spokeswoman Diane Yohe said he received cardiopulmonary resuscitation in the Scripps emergency room, but was pronounced dead at 9:55 p.m.
"He literally was probably on the stage five minutes until it was realized that it was serious," said Tom Wartelle of San Diego, a member of the audience of about 500. "The stagehand came out several times and obviously thought it was part of the act.
"It all blended in very well," Wartelle added. "There were comments from the audience like, 'Take his wallet!' Finally a doctor came from back of the wings, felt for his pulse and realized something had happened. He flipped him over. The audience reaction by then was, 'Boy, this is out of taste.' "
Wartelle said the audience was asked to leave while doctors administered CPR. Paramedics were called and Shawn was transported to Scripps by ambulance. University officials said Shawn's son Adam had attended the performance.
According to Wartelle, Shawn's performance began shortly after 8 p.m. when "he appeared as a disembodied head appearing out of a table. He did a very funny routine with that, and had another actor come out as if he was eating dinner off the table."
The stage lights went dark, then Shawn reappeared, doing a routine in which he was "out of rhythm to some dance music," said Wartelle. "He was obviously moving around and didn't seem to be having any trouble."
Shawn then put aside the microphone he was using, asked if he could be heard without it, and began talking about the end of the world. It was then that he lay down on the stage, remaining motionless, while members of the audience looked on, first amused, then appalled.
"My personal reaction was one of disbelief," said Tom Tucker, an assistant vice chancellor for undergraduate affairs, who had attended the performance with another assistant vice chancellor. "On occasion, a person reads or hears about something like this occurring. But it never occurs on your campus or when you're in the audience.
"Particularly in the case of a comedian where this could very well, early on, have been part of the act."
Shawn leaves a brother and four grown children. Funeral services are pending.
A hugely entertaining and unpredictable man, Shawn had the ability to combine comedic elements with drama and personal insight that brought extra dimension to stage and film roles--and that provided the only touch of excellence for more than one otherwise forgettable opus.
Born Richard Schulefand on Dec. 1, 1929, in Buffalo, N.Y., he grew up in the steel-mining town of Lackawanna, living with his parents and a brother in a single room in back of his father's clothing store.
"If that sounds like we were rich," he told a 1981 interviewer, "forget it. We sold clothes to mine workers and a lot of it was second-hand. Or stolen, I think. But that world shaped me.
"When you look around and you see people into just eating and praying, the rest of the world looks crazy."
His greatest ambition as a child, he said, was to play professional baseball and he had a tryout with the Chicago White Sox that resulted in a contract.
"But I got drafted (into the military) a couple of days later," he said, "and it was kind of good luck--I don't think I'd have made much of a ballplayer, really.
"In the Army, I heard they needed replacements for the USO shows, so I tried out and they accepted me. I could always make people laugh."
Emerging from the Army, he attended the University of Miami ("I went there because I heard all the rich, pretty girls were in Miami") but left school to pursue a career as a standup comic.
In New York, he auditioned successfully for Arthur Godfrey's "Talent Scouts" show, and it was at this point that he shortened his name to Shawn.
"I thought it would help," he said, "To tell the truth, I never knew whether it did or not . . . I didn't win on the 'Talent Scouts' show, and the next year or two were thin, but gradually I worked up enough material for a real act."
He made eight appearances on the Ed Sullivan Show, played the New York Palace with Betty Hutton and Danny Kaye, and then moved to Las Vegas where he appeared in Marlene Dietrich's showroom troupe.
The nightclub work led to legitimate theater: He replaced Zero Mostel in "A Funny Thing Happened on The Way to The Forum," and stage work led to films.
"I never got the Joseph Cotten parts," he laughed. "No--for me, they saved the strange ones."
He was a mincing, lisping Hitler in "The Producers," a heroic transvestite in "Angel," an amorous psychoanalyst in "Penelope" and a crazed surfer in "It's a Mad, Mad, Mad, Mad World."
Shawn also appeared in Max Liebman TV spectaculars and was a regular on the short-lived "Mary" series.
But it was in his one-man show, "The (2nd) Greatest Entertainer in The Whole Wide World," that he truly hit his stride.
The show had a dark underside of apocalyptic ruin, with Shawn emerging like a sleeping vagrant from beneath a decorative mound of crumpled newspapers to spout stream-of-subconsciousness monologues--a tenuously linked garland of lines, bits and thought, and perceptions--lying in apparent coma on stage during intermission, and rising to entertain more afterward.
"It's surreal," he said, "but I think some of the insights are the kind of things people think about later.
"That's the sort of thing I'd like to do for the rest of my life.
"You can't ask a better send-off than that."