Fire in a Paint Booth

On August 12, while the factory was shut down for annual maintenance, an operator was working alone in the pit of the water curtain on a painting line.
The hot work permit had been issued according to the company’s procedures, after having been rejected initially, the loss prevention department having requested an additional cleaning before authorizing hot work operations.
At approximately 5 p.m., a fire breaks out in the pit.
The plant emergency teams act quickly, using fire hose reels, and manage to keep the fire from spreading to a nearby paint booth. What are the lessons learned?