An explosion in Cedar Falls was reported Monday morning around 10 a.m. at a Cedar Falls Utilities electric generating station, destroying half of the building and sending shock waves throughout Cedar Falls.

The explosion happened at the generating station at 2602 West 27th Street in Cedar Falls at around 10 a.m.

Two CFU employees -- Steve Balthazor and Kevin DeSerano -- were inside at the time, according to Betty Zeman, CFU Marketing Manager. They were treated at the scene and declined further medical attention.

The workers were doing a routine test of the combustion turbine at the time, according to CFU officials.

"What was happening today is a routine test of one of the gas turbines that we do annually. So the employees who were working this morning were doing a routine start up of the turbine for testing," said Zeman.

CFU officials are still investigating the cause of the explosion.

Schilling said he was inside City Hall at the time and felt that building shake. Emergency crews got calls from all over Cedar Falls about buildings shaking, they said.

Officials say the explosion, which damaged about half of the station, will not affect CFU's ability to generate power to the city.