An investigation has been launched into a blaze at a former skate park.
Four fire engines and an aerial platform were called to the building on School Street, Preston, shortly before 5pm on Thursday.
The building, which has not been used for the past few months, was well alight when they arrived.
Around 20 firefighters worked to bring the blaze under control.
Part of the roof had collapsed and there was damage inside the skate park.
No-one was inside at the time and nearby buildings were unaffected by the fire.
Crews remained there for several hours as they continued to damp down and asbestos was found in the building.
A section of nearby Bow Lane was closed to traffic while they worked.
The cause of the fire is thought to be suspicious and an investigation is now underway.
Station manager Mark Winder said: “We do believe it is suspicious and we will liaise with the police on the investigation.”