TAMPA — Former All-America center Dwayne Schintzius, who helped Florida to its first SEC championship and three NCAA Tournament appearances, died Sunday at age 43 from respiratory failure.Mr. Schintzius died at 2:45 p.m. at Moffitt Cancer Center, where he was being treated for complications from a failed bone marrow transplant, according to his father, Ken. He was surrounded by his family, including his father, his mother, Linda, and his brother, Travis."He just went peacefully," Ken Schintzius said. "He didn't suffer."Mr. Schintzius, a former Brandon High star, first underwent treatment for leukemia in 2010, and he later had a bone marrow transplant. He had a second marrow transplant in November but had suffered from complications since."He's been in and out of the hospital," Ken Schintzius said. "He spent a few weeks in, and he would spend a few weeks out. Went back in 31 days ago. They put him in the intensive care unit there. He had a problem breathing. He had something similar to fibrosis. And he just couldn't get oxygen. His system just kind of started shutting down early (Sunday) morning."Mr. Schintzius was a 7-foot-2 player who was with the Gators from 1987-90, helping them to their first NCAA Tournament appearance in 1987.Former Gators teammate Renaldo Garcia, now the boys basketball coach at Sickles High, said he had heard from teammates that Mr. Schintzius was ill again but hadn't talked with him since November. And many teammates were unaware of his health status. Garcia, who said he was "shocked" to hear the news, said he was recently talking with former Florida assistant Monte Towe, who asked about Mr. Schintzius."Just a carefree individual who loved to have fun," said Garcia, who played at Tampa Catholic as Mr. Schintzius was across town starring at Brandon, where he was a high school All-American. "He was way more talented than he got credit for. Just a super teammate and a friend. Dwayne, that was my ride home sometimes from Gainesville in my earlier years, before I had a car. He was almost like a big-brother type to us guys from Tampa."Mr. Schintzius started all 110 games he played in at Florida, averaging 14.8 points. In 1989, he was an Associated Press and Sporting News All-American and earned first-team All-SEC honors when he led the Gators in scoring (18 points per game) and rebounding (9.7 per game). He is the only player in SEC history with more than 1,000 points, 800 rebounds, 250 assists and 250 blocks. He holds the Florida record for blocks (272) and is sixth in scoring with 1,624 points."He is probably the least-appreciated great player in school history," said Larry Vettel, a longtime Gator broadcaster. "The fact of the matter is that 7-footers are always held to such a ridiculously high standard. And for him, he could never live up to it. I joked with (former Florida coach) Norm Sloan once that if the O'Connell Center roof leaked, most people would blame it on Dwayne. And it just was kind of the way it was. "He was a great player. He was flat out a great player. But because he was 7-2, he was supposed to average 30 points, 20 rebounds, block 10 shots and help little, old ladies back to their car after the game."Mr. Schintzius was a first-round draft pick (24th overall) of the Spurs in 1990. He played for five other teams — Kings, Nets, Pacers, Clippers and Celtics — during his eight-year career. He made his acting debut in the 1996 comedy Eddie with actor Whoopi Goldberg, playing a Russian basketball player.Although he was one of the most dominating big men ever to play for Florida, his career there ended on a stormy note. After Sloan was fired, Mr. Schintzius was suspended by interim head coach Don DeVoe and ultimately left the team midway into his senior season, reportedly after the two could not come to terms on team rules."What he did for Florida basketball was as much as anybody's ever done," said Bill Koss, a former Gator letterman who has broadcast Florida games for more than 30 years. "It's hard to manufacture size, and he had great size and a great presence. But underneath that was a young man trying to figure himself out, and I think he went for years trying to figure himself out."I really liked Dwayne. I always felt like he was underappreciated. With his size, he was the best big man probably Florida has had as far as skills. A troubled guy, yeah. A lot of situations presented themselves that made it hard for people to truly appreciate him, but he was a good person at heart. I always thought Dwayne had a big heart."Mr. Schintzius received a warm ovation when his name was announced as he attended a Gator basketball game this past season at the O'Connell Center."That was very emotional," Koss said.Both Vettel and Koss said Mr. Schintzius will forever be remembered in Gator folklore for the two free throws he made in a game against Vanderbilt during the 1988-89 season with time expired. The shots sent the game into overtime, where Florida eventually won, sealing its first SEC regular-season title."He hit his free throws," Vettel said. "I think the most important thing to remember is that Florida never went to an NCAA Tournament before Dwayne arrived, and the three years he was in Gainesville, they went to the NCAA Tournament each year. Florida had never won an SEC championship when Dwayne arrived, and in his third season the Gators won the SEC title."Ken Schintzius said he and his son, Travis, will begin making funeral arrangements today."He was my hero," Ken Schintzius said. "He never complained. He never said, 'Why me?' He just … when (the doctors) asked him to do something, his answer was, 'You know, whatever it takes.' That was his motto."He was a good son. He was a good person. Had a great sense of humor. You'd walk into a room, and the whole room would just light up. I'm his dad. I'm probably tooting his horn. He was good to us. I'm going to miss him a lot. He was my friend, my buddy. He's going to be missed, and I'm going to miss him. Terrible, terrible loss."Time staff writer Joey Knight contributed to this report.