WATERLOO - A bomb threat forced the evacuation on Friday of a GMAC Mortgage Corp. building in Waterloo.

Waterloo police and fire departments responded at about 1:15 p.m. to an anonymous call about a bomb at 3451 Hammond Ave. GMAC is one of the Cedar Valley's largest employers.

The building was evacuated, but police who searched the structure found no evidence of explosives.

Waterloo Police Lt. Mike McNamee said police are treating the call as a hoax, and continue to investigate.