Theory over town tyre inferno

A massive fire raging at a north Shropshire industrial estate was most likely to have been caused by "self-ignition", investigators said today.

The revelation emerged today as firefighters continued to tackle the blaze involving an estimated 2,000 tonnes of waste rubber at Kingpin Tyres on Wem Industrial Estate.

While arson has not been ruled out, fire investigators are now examining the strong possibility that a combination of factors sparked the blaze.

The fire started early on Tuesday morning and sent plumes of thick acrid smoke, which could be seen for 20 miles, into the sky.

A combination of warm weather, moisture in the atmosphere and the size of the pile of waste rubber could have triggered the blaze, which was tackled by 30 firefighters at its height.

Martin Timmis, head of operational response at Shropshire Fire and Rescue Service, today said the material in the pile of rubber which burst into flames is prone to "self heating".

He said: "In many respects it's a bit like straw which can catch fire when piled up.

"Warm weather can add to the risk of a fire starting but rain can too. All it takes is a bit of moisture in the air for it to happen. It's deep science but this material can self-heat.

"At this stage we have not conducted a thorough investigation but it's most likely that the product we are talking about is susceptible to self ignition so that looks like the most likely cause right now."

Teams of about 10 firefighters are now taking turns on site to fight the flames as they bring the fire under control, he added.

"The level of manpower varies from day to day at the moment, but we have started trying to use a specific technique which involves about 10 crew members at a time being on site," he said.

Latest estimates suggest the fire, which has already raged for six days, could take weeks to burn out.

Environment Agency experts have also been on site to sample air and water quality amid fears over pollution.

And about 3,000 leaflets about the fire have been delivered to Wem residents to advise them on how the fire is being tackled and reassure people that the smoke billowing from the estate is not toxic.

By Tom Johannsen