A fire at a large former dive school is believed to have been started maliciously.
At 3:50am this morning several 999 calls were recieved to the large building on fire near Jewsons in Hayle.
The original caller stated the shed on fire was large, approx 20 x 5 metres and on the reciept of the initial call three major fire appliances with eighteen crew - one from Camborne and two from St Ives were mobilised.
The derelict dive school was well alight when crews arrived.
By 4:35am firefighters were using two main jets and a ground monitor being supplied with water from a hydrant in Foundary Square via water shuttle. Crews are also using two breathing apparatus.
The fire in the building was extinguished just after 6am and after a search by fire crews wearing six breathing apparatus it has been confirmed that all persons have been accounted for.
Devon and Cornwall Police secured the site and a footpath beside the warehouse and Jewsons has been closed due to the unstable building.
A spokesman said: "This fire is believed to have been started maliciously."