Nine people were injured, four of them hospitalized, when the balcony collapsed Saturday at the home.
Video shows several people crowded on the balcony when it fell.
RELATED: 9 injured after balcony at beachfront Malibu home collapses, plummets onto rocks below
Witnesses say they had gathered for a birthday party when the celebration took a terrifying turn.
The home has been red-tagged. Investigators believe the deck's integrity and the weight of too many people combined to cause the collapse.
"The property in question had a valid short-term rental permit with the City in line with the City's short-term rental ordinance," the city of Malibu said in a statement Monday. "Malibu Code Enforcement is investigating any potential violations of occupancy limits of that permit or any other issues with that property, and Building and Safety staff are investigating the incident as well."