Al O'Leary, who handles public relations for the New York City Transit Authority, was surprised at all the phone calls about the dead man who rode the subway Monday morning.

"It's not unusual," he said. "We move 4.2 million people every day. How could you not find a deceased person now and then?"

He noted that on average, two people every month take their own lives by jumping in front of New York subway trains. "It wouldn't be my choice," O'Leary said. "I'd rather be shot by a jealous husband."

But who was the dead man overlooked by hundreds of passengers during rush hour on the northbound No. 1 train? How long was he slumped in a seat, heart stopped, on one of the busiest lines in one of the busiest cities on Earth? And just how many other people die on the subway? "You'd have to ask the police," O'Leary said.

New York City police officer Kevin Tyrrell consulted a computer. "Hispanic. Five-foot-six. One hundred and seventy pounds. Forty to 50 years old." The corpse was wearing jeans, a gold polo shirt and black boots. He had 20 cents, a watch and a comb in his pocket.

"Sounds like he could be undomiciled," Tyrrell said, meaning homeless. "Then again, it sounds like me. Let's see. Yup. I have 60 cents in my pocket right now."

But how does a dead passenger go unnoticed in the City That Never Sleeps? "This is a large city," he said. "A lot of people sleep on the subways. Someone wrote a song about it once. I think it was Petula Clark."

But who was Dead Man Riding? "You still want to give that legs, huh?" Tyrrell deadpanned.

He was riding a train that left South Ferry in the lower tip of Manhattan at 10:29 a.m., and could have been traversing the route for hours. A passenger discovered him at 11:01 at the West 96th Street stop. The train was pulled out of service at 11:14.

Soon, a medical examiner categorized him as "Investigate DOA." In a year, Tyrrell said, the city has had 766 Investigate DOAs. "A lot of people are found dead in this city, on park benches, under park benches, in shanties and cardboard boxes." Just the other day, a "male, black, 47" was found dead on a bench on the west side of Central Park.

The last time a passenger was found dead on the subway, he said, was May 18. A motorman checking the A Train before parking it at a yard at 207th Street discovered a "male black in his forties." He has not been identified.

The gallows humor, O'Leary reported, has already surfaced. "I heard that Regis and Kathie Lee were talking about eating fresh crabs last night. They said, 'At least we killed them humanely: We made them ride on the subway for five hours.' I'm going to tune in my VCR tonight to see what Leno and Letterman do with this."

Tough town.