Authorities are investigating whether heating equipment caused a large fire at the site of an amusement park being constructed in Waterloo. Television station KWWL reports that firefighters were called to the Lost Island Theme Park site Thursday night. Officials said the fire destroyed an entrance shelter for one of the rides. Park owner Eric Bertch said it appears some temporary heating caught a blanket on fire. The $100 million addition to the Lost Island Water Park is tentatively scheduled to open in May or June. Bertch said the fire will not delay the park's opening. No one was injured in the fire.