A helicopter that crashed into a Houston radio tower, killing all four people aboard and starting a fire below, was on an air tour flight at the time, authorities said.

Four people aboard a helicopter were killed when it crashed into a radio tower in Houston and burst into flames, officials said. The helicopter went down just before 8 p.m. Sunday in a neighborhood east of downtown after taking off from Ellington Field,

Police urged residents near the crash to call 911 if they find anything on their property that could help in the investigation.