On Friday night, Britain has witnessed its worst traffic-related accident in 20 years. Seven people are confirmed dead in the crash that took place on the M5 motorway. There are fears that the number of fatalities could go up to 12, as rescuers are still searching for bodies amid the mangled remains of 34 vehicles.

The reasons for the crash are still unknown. However, forensic experts have already launched a probe. Among those causes being considered at this time are bad weather conditions, bonfires and a firework display at a nearby rugby club, which could have distracted some of the drivers, leading to the pile-up.

Investigators are speculating that smoke from the fireworks and the bonfires must have combined with thick fog and rain, severely limiting the degree of visibility on the highway. Police are following up on the rugby club's fireworks display to check if proper safety measures were in place.

The Taunton Rugby Club is just 300 yards from the crash site. The crash site itself was covered in thick fog and smoke, for about 200 yards between M5's 24th and 25th junctions. In addition, weather forecasters cautioned that bonfires burning nearby could have made conditions worse.

The particles bonfires release encourage fog droplets to form, said Gareth Harvery, a MeteoGroup forecaster, to the Express.

The crash is the worst in the UK since 1991, when 10 people were killed and 25 injured in a huge pile-up on the M4 in Hungerford, Berkshire.