It was truly miraculous that a series of accidents involving some 130 cars on a fog-shrouded bridge in Kent did not result in deaths, British police said.
Witnesses described drivers travelling at high speed without headlights on as they crossed the four-lane A249 bridge from the Isle of Sheppey to the Kent mainland. The monster pile-up on Thursday (NZ time) is believed to be the largest in Britain to take place in fog.
Eight of those hurt in the collisions, which took place about 7.15am, have serious injuries.
Ambulance crews said 33 casualties needed hospital treatment in what were described as horrendous scenes. A further 200 people were triaged by paramedics.
There were reports that the crashes continued for up to 10 minutes and further collisions were prevented by the quick thinking of a lorry driver who parked his lorry across a roundabout to stop further vehicles driving on to the crossing.
Chief Inspector Andy Reeves, from Kent Police, said: "From my perspective, it's truly miraculous. It's very fortunate there were no fatalities. Visibility was very bad, down to 25m in thick fog, and clearly it will be a key factor in our considerations. But at this stage we haven't yet determined what caused the start of the crash."
Drivers described being able to see no further than two or three car lengths ahead before the crashes, which left a trail of buckled vehicles stretching for several hundred metres, including cars thrown on top of each other and others flipped on to their roofs.
Firefighters had to free six people from their vehicles. Driver Martin Stammers, from Minster, Kent, said: "I've never seen anything like it. All you could hear was cars crashing. We got out of our car and it was eerily quiet."
The driver of a damaged van, who declined to give his name, said: "It was so foggy, you couldnt see anything in front of you. By the time there was a problem, it was too late. The bridge shouldn't have been open."
The crossing, which opened in 2006, does not have lighting.
Sittingbourne and Sheppey MP Gordon Henderson said he had previously had concerns about this and said he would question the authorities about the accident.
The crossing was closed for more than nine hours.