A block of flats was evacuated on Friday night as more than 30 firefighters battled to control a blaze on Carnoustie's High Street.
Three shops in the Angus town were badly damaged by the fire, which was chanced upon by a fire crew returning to their station shortly after 8pm.
The crew had just extinguished a fire in an empty chalet at Seaton caravan park in nearby Arbroath when they saw a row of three shops on fire.
Although they were on the scene "almost immediately" the fire took five hours to bring under control — with five other engines and an aerial rescue pump from Dundee needing to be called into action.
The fire was contained to the single-storey shops, but firefighters feared an adjoining block of residential flats was in danger and, after using covering jets to prevent the blaze spreading, they evacuated the homes.
Tayside Fire and Rescue group manager Roy Dunsire, who was the incident commander at the scene, said: "A fire engine from Carnoustie was returning from a fire call to Arbroath when it happened to come across the fire, so they were almost immediately on scene and able to start tackling the fire.
"However, the fire was spreading very quickly and threatening an adjoining block of flats. Fire crews therefore reacted very quickly to this risk and, assisted by the local police, evacuated the flats and set about using covering jets to protect the flats from becoming involved in the fire."
The affected shops were the Perfect Laundry launderette, the Carnoustie Country Larder delicatessen and a vacant premises.
Tayside Police and Tayside Fire and Rescue now plan to carry out a joint investigation in order to establish the cause of the blaze.
The fire at the caravan park in Arbroath broke out around 6.30pm and was well-established when firefighters arrived.
Fire crews wearing breathing apparatus quickly dealt with blaze in the empty chalet though there was an extensive amount of damage to the property.
A further joint investigation between the fire service and police will be carried out.
Video courtesy of OurCarnoustie.co.uk.