Frank Wills, the Watergate security guard who discovered the 1972 break-in that led to President Richard M. Nixon's resignation, died Wednesday in University Hospital. He was 52.
The hospital did not give the cause of death.
Friends of the family said he suffered a brain tumor and had been ill for several months.
Though Wills had spent the years since the break-in in relative obscurity, his discovery of the burglary at the Washington, D.C., hotel-office complex thrust him briefly into the spotlight.
He later played himself in "All the President's Men," a movie about the scandal.
Early on June 17, 1972, Wills found a piece of gray tape over a door latch leading into the Watergate complex. Thinking a shift worker had put it there to make it easier to get in and out of the building, he pulled it off and stuffed in into his pocket.
When he later found a second piece of tape over the lock, he called police.
Wills followed the officers to the Democratic National Committee offices in the Watergate. Inside, they found five men: James McCord, Bernard Barker, Eugenio Martinez, Frank Sturgis and Virgilio Gonzales.
The bungled burglary led to discoveries of conspiracy, obstruction of justice, illegal use of the FBI and CIA and illegal campaign contributions, all of which ultimately drove Nixon from the White House.
On the 20th anniversary of the break-in, Wills told a reporter that he had a premonition while walking to work that night.
"It just seemed the closer I got to that building, there was something unusual," he said. "It turned out to be quite unusual."
He quit the Watergate soon after the break-in and had trouble finding work.
He said one Washington university told him it feared losing federal funds if it hired him. Eventually, Georgetown University hired him as a security guard.
Wills returned to North Augusta, S.C., in 1990 to take care of his ailing mother.
The two lived off her $450-a-month Social Security check until her death in November 1992.