Poor visibility due to heavy fog is believed to be one of the primary causes of the pileup, with some witnesses reporting they could only see about 30 feet in front of them before the crash. There were reports from some drivers that the collisions went on for ten minutes, as other vehicles caught up to the scene of the accident and were unable to stop in time.
Chief Inspector Andy Reeves told the BBC, "It was...very hazardous. It was described to me as a very thick fog and it was certainly low visibility at the time." Cars, vans, semis and even a loaded car carrier were involved in the wreck, which will likely keep the bridge closed for the remainder of the day. Scroll down for helicopter footage of the aftermath.