Background: Allison was born December 3, 1937 in Miami, FL. He entered his first race as a senior at Archbishop Curley-Notre Dame High School in Miami. Since he was only 17, he had to have his parents' permission so he thought when his mother said ok, it was forever, but she thought it was for only one race.
Context: On June 19, 1988, at the midpoint of the 1988 season, Allison crashed on lap 1 of the Miller High Life 500. Initially he survived a head-on hit into the outside barrier but then suddenly Jocko Maggiacomo t-boned Allison in the driver's side of the car, nearly killing Allison. When he reached a local hospital he was initially declared dead, but subsequent medical assistance saved his life. Beginning from a vegetative state, Alison entered a rehab program. As a result of his massive injuries he retired from driving in NASCAR. In 1992 his younger son, Clifford Allison, was fatally injured in a practice crash for the NASCAR Busch Series race (now Xfinity Series) at Michigan International Speedway. Bobby Allison was elected to the International Motorsports Hall of Fame in 1993.  Later in 1993, his son Davey was killed in a helicopter accident at Talladega Superspeedway. Three years after these major tragedies, he and his wife Judy divorced. Four years after their divorce, while attending their daughter-in-law's wedding, they reconnected. They were remarried in July 2000 and remained together until her death in 2015. He was inducted into the Motorsports Hall of Fame of America in 1992, and inducted into the NASCAR Hall of Fame in May 2011, along with Lee Petty, Bud Moore, David Pearson, and Ned Jarrett.  Allison is one of eight drivers to have won what was then considered a career Grand Slam (an unofficial term) by winning the sport's four majors: the Daytona 500, the Winston 500, the Coca-Cola 600, and the Southern 500. Only seven other drivers have accomplished this feat: Richard Petty, David Pearson, Darrell Waltrip, Dale Earnhardt, Jeff Gordon, Jimmie Johnson, and Buddy Baker.
Question: Did his family have any other tragedies?

Answer:
his son Davey was killed in a helicopter accident