Contractors Pete Marquis have been at the Church Street site all day to remove the building after an engineering assessment ruled it beyond saving following a blaze at approximately 6.45pm on Thursday (May 19).
Pete Marquis, director of the firm drafted in to complete the demolition, said the back wall which was close on 100ft high had proved a difficult part to remove.
He said: “It's a tough old building. It’s been up since the 1920s.
“It’ll take a bit of machining down but we’re away now, we’ve got that height out of the way.
"It’ll be middle to the back end of next week when it’s done but we’re hoping that we can return these streets to normal by Monday evening and fence ourselves in there."
Lancashire Police announced yesterday that a 14-year-old boy was arrested in connection with a joint investigation into the fire with Lancashire Fire and Rescue Service.