SHANKSVILLE, Pa. Searchers have recovered the cockpit voice recorder from United Flight 93 that could reveal whether passengers tried to overpower the hijackers.
The black box was found Friday evening buried 25 feet deep inside the V-shaped canyon the airliner gouged as it crashed into a field in rural southwestern Pennsylvania. All 45 people aboard the San Francisco-bound flight from Newark, N.J., were killed.
A few miles from the crash scene, Gov. Tom Ridge spoke at a candlelight vigil Friday evening and lauded what he called the heroism of the passengers.
"The passengers on that plane decided to fight back against their hijackers," Ridge told a crowd of about 3,000 in Somerset. "They undoubtedly saved hundreds, if not thousands, of lives in the process. They sacrificed themselves for others _ the ultimate sacrifice."
Several passengers made cell phone calls before the plane crashed, saying they had been hijacked and were trying to decide how to thwart the terrorists' plans. They found out during those calls that two other planes had just crashed into the World Trade Center.
Deena Burnett said her husband, Thomas Burnett, 38, called her from the hijacked plane and said: "I know we're all going to die _ there's three of us who are going to do something about it."
Deputy Defense Secretary Paul Wolfowitz said that the military had been monitoring the plane and was in a position to intercept it.
"I think it was the heroism of the passengers on board that brought it down, but the Air Force was in a position to do so if we had had to," he said on PBS's "NewsHour With Jim Lehrer."
Sen. Arlen Specter, R-Pa., said Friday that he is looking into the possibility of recommending the Presidential Medal of Freedom for passengers aboard the flight.
FBI spokesman Bill Crowley said the plane's voice recorder, designed to record the final 30 minutes of conversation in the cockpit, appeared to be in relatively good condition. It was sent to a National Transportation Safety Board laboratory in Washington to be analyzed.