According to the report, Warren's fire department received a call at around 9AM this morning, only to find two injured and "a small fire" stemming from the explosion. A General Motors spokesman apparently put the number of injured parties at one, so there is still some confusion about the number of people affected by the incident at this point.
A HAZMAT team was dispatched to the Tech Center and the building has been evacuated, with all employees accounted for. Detroit NBC affiliate WXYZ is on the scene with a live feed that you can watch here. The extent of the injuries and damage, along with what caused the explosion, are not immediately clear, but we will have more details as they become available, so stay tuned.
*UPDATE: Video added after the jump.
** UPDATE: In a statement added after the jump, GM now says the explosion was caused by "extreme testing of a prototype battery" that is "unrelated to the Chevrolet Volt or any other production vehicle."