William “Tiger” Warren, founder and chairman of the Macheezmo Mouse restaurant chain, was killed Saturday when the float plane he was piloting plunged into the Columbia River just after takeoff. He was 48.

His three sons, Jack, 14, Will, 13, and Rob, 9, also died in the crash. The boys were spending Thanksgiving with their father and flying to the family’s summer home in Washington.

Warren’s 8-year-old daughter, Lucy, had stayed behind in Oregon with her mother, Geraldine, who was divorced from Warren and now is married to Portland stockbroker H. Gerald Bidwell. Warren, his ex-wife and Bidwell had just emerged from a long ordeal in court as witnesses against a disgruntled investor who blamed Bidwell for a $50,000 stock loss.

Warren and his wife were in the middle of what had become a bitter divorce in 1994 when he took Macheezmo Mouse public, turning his shares into a $9.2 million investment in one day. But the chain of 13 Mexican-style restaurants since has struggled, despite its wide menu featuring many low-fat dishes aimed at attracting what the company saw as a growing market of health-conscious customers, including aging Baby Boomers.

Warren had worked for Esco as a steel salesman before founding Macheezmo Mouse in 1981. Before that, he had a short career as a filmmaker.

Warren’s movie “Skateboard,” one of the first features on the sport, was produced in the 1970s in Los Angeles.