The BMW was approaching the tunnel at "a high rate of speed" but it hit the freeway barrier wall, "rupturing the fuel tank," the Minnesota State Patrol's report says, noting the crash happened at 9:39 p.m. on the westbound side of Interstate 94.
Video of the crash (warning, it's graphic) shows the BMW crashing into the side of the tunnel and then bursting into flames, coming to a rest inside the tunnel.