Part of a Rolls Royce foundry in Derby has been damaged after a fire spread from a furnace.
The fire in the manganese shop at the company's light alloy foundry in Osmaston Road started at around 1230 GMT on Monday.
A fire service spokesman said a manganese pot burst at the foundry, but the no-one was injured in the incident.
Firefighters in breathing equipment put out the flames.
The Derbyshire Fire and Rescue said a full investigation is under way into the incident.
Three pumps and a high-rise ladder unit responded to the fire, which took less than an hour to extinguish.