Kulwicki grew up in Greenfield, Wisconsin, a suburb of Milwaukee known for its Polish-American neighborhoods, near the Milwaukee Mile racetrack. After his mother died, his family moved in with his grandmother, who died when Kulwicki was in seventh grade. A year later, his only brother died of a hemophilia-related illness. Kulwicki attended Pius XI High School, a Roman Catholic high school in Milwaukee, and received a bachelor of science degree in mechanical engineering from the University of Wisconsin-Milwaukee in 1977.

Kulwicki died in an airplane crash on Thursday April 1, 1993. He was returning from an appearance at the Knoxville Hooters in a Hooters corporate plane on a short flight across Tennessee before the Sunday spring race at Bristol. The plane slowed and crashed just before final approach at Tri-Cities Regional Airport near Blountville. The National Transportation Safety Board attributed the crash to the pilot's failure to use the airplane's anti-ice system to clear ice from the engine inlet system.  Kulwicki was buried at St. Adalbert's Cemetery in Milwaukee; the funeral was attended by NASCAR President Bill France, Jr. and numerous drivers. Kulwicki's racecar transporter was driven from the rainy track later that Friday morning while other teams and the media watched it travel slowly around the track with a black wreath on its grille. In 2008, Kyle Petty described the slow laps as "the saddest thing I've ever seen at a racetrack... We just sat and cried." Kulwicki had competed in five NASCAR races that season with two Top 5 finishes, and was ranked ninth in points at his death. In his career, he had won five NASCAR Winston Cup races, 24 pole positions, 75 Top 10 finishes, and one championship in 207 races.  His car was driven by road course specialist Tommy Kendall on road courses and by Jimmy Hensley at the other tracks. It was raced for most of the 1993 season until the team was sold to Geoff Bodine, who operated it as Geoff Bodine Racing.  Kulwicki had been selected to compete in the 1993 International Race of Champions (IROC) series as the reigning Winston Cup champion. He competed in two IROC races before his death, finishing ninth at Daytona and eleventh at Darlington. Dale Earnhardt raced for Kulwicki in the final two IROC races, and the prize money for those races and their fifth place combined points finish was given to the Winston Cup Racing Wives Auxiliary, Brenner Children's Hospital and St. Thomas Aquinas Church charities.

how old was he when he died?