Officials say a former Dow Chemical headquarters complex building in Michigan that was being demolished has unexpectedly collapsed.
No injuries were reported in the Thursday morning collapse of the six-story building at Dow's campus in Midland, about 105 miles (169 kilometers) northwest of Detroit.
Authorities say no one was at the building at the time. The company says the structure had been weakened during the demolition process, leading to its collapse. The collapse created a cloud of dust, but Dow says any potentially hazardous materials had already been removed.
Dow has an emergency response team on site. The Midland Fire Department says a small portion of the structure remained standing.