A clean-up operation at a Padiham recycling centre gutted by a huge blaze was under way.
Flames ripped through tons of plastic bales in the storage yard of the facility in Park Road last Wednesday.
Piles of charred remains were being removed by lorry from the former Padiham tip site in the wake of the devastating fire.
Building inspectors had been due to assess the safety of a wall which was damaged in the incident.
The suspected arson attack was branded “reckless and extremely dangerous” by police who are still hunting for the culprits.
Anyone with information can contact Crimestoppers anonymously on 0800 555 111.