Mother of Uber CEO Travis Kalanick killed in boating accident Kalanick's father was also injured in the accident, officials said.

 -- Bonnie Kalanick, the mother of Uber CEO Travis Kalanick, has died in a boating accident near Fresno, California, according to a statement from the ride-sharing company.

His father, Donald Kalanick, was also involved in the accident and is in "serious condition."

"Last night Travis and his family suffered an unspeakable tragedy," Uber said in a statement on Saturday. "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."

According to the Fresno County Sheriff's Office, Bonnie Kalanick, 71, died after the boat she and her husband, Donald, 78, were riding hit a rock in Pine Flat Lake in the eastern part of the county.

An internal e-mail, obtained by ABC News, was sent to employees on Saturday alerting them to the news:

"Team: I’m writing to share some heartbreaking news. Last night Travis’ mother died in a tragic boating accident near Fresno. His father, who was also on the boat, is in serious condition and is being treated at the hospital. This is an unthinkable tragedy as everyone in the Uber family knows how incredibly close Travis is to his parents," the email said.

"Our thoughts and prayers are with him and his family, and we wanted to let his Uber family know right away.

I know we all want to do whatever we can to help, and I’ll communicate again as soon as there is something we can share.

Kalanick was at the Kentucky Derby with his parents three weeks ago.