"What happened on Thursday night in Orinda was horrible. I feel for the families and neighbors impacted by this tragedy. We are working to support them," Chesky said in a tweet.
People with knowledge of the transaction say the woman who rented the home lied to her Airbnb host, saying she was renting it so her asthmatic family members could escape wildfire smoke. More than 100 people had gathered for the party, police said.
House parties have long been an issue for Airbnb.
In 2018, Airbnb permanently banned a man who crammed more than 250 people into an Airbnb rental in Seven Hills, Ohio, for an unauthorised New Year's party while his host hid in a bedroom.
And in July, two people were killed during a party at an Airbnb in Pittsburgh.
- AP