Isla Vista Beach Party at UCSB Turns Chaotic with Injuries, ODs

The college community that abuts UC Santa Barbara was out of control Saturday, after a rager left a bunch of people injured and hospitalized.

It was actually an annual event, called "Deltopia" ... and it's become wildly popular in the town of Isla Vista.

There were injuries -- one girl fell from a roof -- and OD's ... and there was enough that the Santa Barbara Fire Dept. declared the party a "multi-casualty incident." The SBFD said there were "multiple medical emergencies including multiple severe traumas."

The party went on through the afternoon Saturday ... it got so crowded that the EMTs had trouble getting the injured out of the area.

It's been a wild couple of days in IV ... on Friday there were arrests made and citations issued.