A prototype battery explosion blew out windows Wednesday at a building on the campus of the General Motors Tech Center in Warren. GM said five people were looked at by medial personnel but only one was taken to the hospital. Warren Fire Chief David Frederick said firefighters got the call at about 8:45 a.m. "Our guys did a great job, they were there within five minutes, and did a fantastic job knocking the fire down and getting everybody out. Everyone was safe," Frederick said.