A 19-year-old woman was in critical condition and 10 people were in serious condition after intoxication-related injuries during the annual Independence Day “floatilla” off Waikiki, a lifeguard spokeswoman said.

Lifeguards estimate 8,000 to 10,000 people attended the party and hundreds had to be rescued from the water.

Honolulu Emergency Services Department spokeswoman Shayne Enright said lifeguards were extremely busy and stayed overtime until 7:30 p.m. because of the event. She said the woman was in critical condition due to intoxication. All the 10 others who were in serious condition had alcohol-related injuries, and the victims ranged from age 17-26, Enright said.

Hundreds of people in various motorized boats and inflatable water toys were in relatively shallow waters about a half-mile offshore as part of the event, the Department of Land and Natural Resources said earlier in the afternoon.

DLNR assigned 14 Division of Conservation and Resources Enforcement officers to the area, using a boat and seven jet skis, DLNR spokesman Dan Dennison said, in a release. Joining them were city lifeguards and two U.S. Coast Guard patrol boats.

Due to brisk off-shore winds, enforcement officers were asking event-goers to move closer to shore and to moderate alcohol consumption, Dennison said.