Battalion Chief William McGovern was last seen alive on the morning of Sept. 11 around the 30th floor of Tower One in the World Trade Center, his fellow firefighters told his wife, Mary.

Knowing her outgoing, assertive husband did not leave before the tower crashed to the ground after the terrorist attack was no surprise to Mary McGovern. Knowing his record for saving lives, she said, "He was going to make sure that everybody got out before he got out."

In January 1988, he and another firefighter "saved the lives of two children in a Bedford-Stuyvesant blaze" in Brooklyn, she said. They ran into a building, crawled on their hands and knees to stay below the smoke and found a young brother and sister lying on the floor. The boy was not breathing. McGovern and other firefighters got both children out and resuscitated the 7-year-old boy. In a newspaper account at the time, McGovern, 49, of Smithtown, was quoted as saying, "I'm thankful I could give him a second chance. I saw him come back to life. It's the greatest experience I ever had."

Mary McGovern said her husband must have been one of the first firefighters at the World Trade Center, because the 2nd Battalion, which he led, was stationed only a quarter of a mile away. She described her husband as "a larger-than-life type guy. When he walked into the room, everyone knew he was there. He liked to entertain and make sure everyone was having a good time - lots of laughter, lots of jokes."

McGovern was in his late 30s when his daughter, Katie, now 11, was born. With Mary McGovern working daytime hours as a bank officer, William McGovern, who was often at home because of irregular hours as a firefighter, took charge. "She was the delight of his life," Mary McGovern said. "He was a class parent. She's on a swimming team. He took her [to meets]. There's going to be a lot of hard time for her."

And for his wife as well. His death "is hard to believe. Every day I expect to see him burst in the door," she said.

In addition to his wife and daughter, McGovern is survived by a son, John, 21, of Boston; his mother, Julia McGovern, of Island Park; two sisters, Kathleen DeCasper, of Island Park, and Marilyn Zurica, of Valley Stream; and two brothers, John, of Long Beach, and Patrick, of St.James.