The mother of Uber CEO Travis Kalanick died, and his father was seriously injured, in a power boat accident on Pine Flat Lake last Friday, according to a Fresno County Sheriff’s report.

The couple hit a submerged rock at higher speed, and the boat quickly sank in the afternoon of May 26. It took several hours before passing boaters recognized a debris field and called 911 for help.

The responding Fresno Sheriff’s helicopter spotted the couple on the shore and landed to give emergency care. Bonnie Kalanick, 71, was found to have already succumbed to her injuries.

Donald Kalanick, 78, was given emergency care, then transported by helicopter to Fresno’s University of California’s Table Mountain Rancheria Trauma Center at Community Regional Medical Center, level 1 trauma center. Mr. Kalanick is expected to survive.

Travis Kalanick’s brother, Cory Kalanick, is a Fresno firefighter. The 15-year veteran exhibited heroic bravery on March 29, 2015, when he charged into what was described as a raging wall of flame and smoke to rescue Fire Captain Pete Dern, was standing on a burning roof that collapsed. KTLA 5 News reported that Dern suffered third and fourth degree burns over 70 percent of his body, but he survived.

Travis Kalanick on May 6 posted a picture on Twitter with his parents at the Kentucky Derby with the comment: “Hello Louisville!! 1st derby with Mom and dad.”

Uber Technologies, Inc. issued a statement: “Last night Travis and his family suffered an unspeakable tragedy. His mother passed away in a devastating boating accident near Fresno and his father is in serious condition. Our thoughts and prayers are with Travis and his family in this heartbreaking time.”

Travis Kalanick and Garrett Camp founded Uber in 2009. The private company is the biggest venture capital unicorn, with a value of $68 billion, according to CB Insights. The company has operations in 60 countries and 334 cities. Uber doubled its workforce to 30,000 in the last two years, and is constantly rumored to be planning the largest public offering in the history of the planet.