Unedited footage of a multi-car pile up in Michigan [Graphic content]

This really is terrifying.

An onlooker films the unfolding events as trucks and cars collide in snowy conditions on Michigan Highway I-94. Ultimately, 150 vehicles would become entangled in the mess. Powerless to do anything about it, you can hear the panic in the passerby's voice as he moves towards the highway around half-way through the footage. One person was killed and a further 23 were injured. We really do only urge you to watch this if you're not easily upset. http://youtu.be/W9fI5M6_XVk