RESIDENTS were warned to stay indoors and keep windows closed as more than 70 fire-fighters tackled the blaze on White Lund industrial estate.

Police evacuated the site and other surrounding businesses and shops and there was traffic chaos as the estate was cordoned off.

Southgate, the Lancaster and Morecambe by-pass, Ovangle Road, and part of Mellishaw Lane were all shut.

The first fire crew from Morecambe was confronted with smoke pouring out of the roof of the building.

Bangs and explosions could be heard from inside the building.

And after assessing the blaze, they put Operation Merlin - Lancashire's multi-agency response plan for serious chemical incidents - into action.

"The fire developed quickly inside the warehouse and within 10 minutes thick smoke had filled the entire building and flames appeared through the roof," says Sub-Officer Tim Murrell, of Morecambe.

"The products generated by the fire were hazardous, with flammable, toxic, corrosive, oxidising and water reactive chemicals involved.

"This hampered operations considerably and the wind direction changed several times, causing fire-fighters to abandon their vehicles to avoid contamination."

Michael Laws, Divisional Officer with Lancashire Fire and Rescue, told the Citizen at the scene: "We were faced with a severe fire involving a building containing a cocktail of chemicals. At all times there was a risk of explosion and of it spreading to other buildings."

Safety worries prevented fire crews from entering the building instead they focused on trying to control the smoke to protect residents.

Mr Laws said it was not yet clear how the fire started, adding: " We are carrying out a full investigation but we do not think it is anything suspicious. We should know within a week."

Fire was contained to one building which the first fire-fighters were not able to enter until around 4pm, with ambulance crews on stand-by.

Water supplies from all over white Lund were utilised by crews, with the pressure being increased by United Utilities.

At its height 11,000 litres of water was directed onto the inferno every minute.

Director of public health Dr Frank Atherton, who spent the day assessing the situation, said: " The direction of the smoke was the most important thing to check out. The good news is that it was dense but there was no specific chemical threat."

The blaze came only six weeks after a large number of crews were deployed to Morecambe Metals, a scrap yard on the same estate, when a massive blaze took hold.