A fire has caused extensive damage to the Foyle Meats processing plant in Londonderry.
It took firefighters three hours to bring the blaze under control.
Five workers were in the building in the Lisahally area of the city at the time.
They tried to tackle the fire themselves before calling the Fire Service.
A Fire Service spokesman said the fire broke out in the piping of the processing plant due to the build-up of residual fat.
When the five workers noticed the pipes glowing red, they called the Fire Service.
Station officer Martin Jeffrey said the processing plant was extensively damaged.
"It was extremely difficult to get it under control because the fire was in the pipework of the processing plant," he said.
"Because we couldn't break into the pipework, it was very difficult to contain and find out where the fire actually started and where it had spread to."