ARLINGTON, Texas (AP) _ Rioters smashed windows, looted souvenir stores and stole cash registers at Six Flags' Hurricane Harbor.

A large fight broke out Friday night during a party sponsored by a radio station, forcing the water park to close early.

Investigators are trying to determine what sparked the melee, and remained at the park early Saturday morning gathering evidence.

Arlington police Officer Doug Hirschman said several people received cuts and scrapes but there were no major injuries. Thousands of young people were at the park at the time, but it's unknown how many took part in the fight.

Police made no arrests, Hirschman said, because they believed it was more important to calm the situation and care for visitors and employees.

The switchboard at Hurricane Harbor was closed late Friday night.