The vans were at the rear of a derelict office block and were completely destroyed. Two single-storey units and a small part of the building’s facade were also damaged. One man was treated for burns and taken to hospital. Station Commander Mick Palmer, who was at the scene, said: "There was a lot of heavy smoke which prompted 32 calls to the 999 control officers. Crews from Park Royal, Wembley, Acton, Ealing and Willesden attended.