Crews from Blackpool were called to a 'suspicious' blaze after a mattress was set on fire close to the main exit route of a block of flats.
Firefighters were called to the incident, which fire bosses said posed a "severe risk to life", on Dinmore Avenue at around 11.15pm on 13 March.
Emergency services arrived to find that the fire had been put out by a resident who heard "breaking glass" and extinguished the blaze using a garden hose.
The fire is one of at least 'half a dozen' thought to have been started deliberately in the Grange Park area in the past year, say fire services.
Watch Manager Warren Topp said: "The Fire Service were called to a fire in the entrance of a three-storey block of flats late yesterday evening. The Fire started in a mattress that had been discarded adjacent to the final escape door and spread vertically up the building very quickly.
"Luckily one occupant was awake and was alerted when the fire cracked the external glazing of the building. He alerted the other occupants and grabbed a garden house to extinguish the fire whilst another quick thinking occupant called the Fire Service.
"Purpose built flats built at this time have no fire alarm systems in the means of escape so it’s imperative that the means of escape are kept clear and free of combustible items. The fire and heat caused severe damage to six square metres of the building facia."
The fire is being treated as suspicious and fire services are working with police on a joint investigation.
Nobody was injured during the incident.