Four people managed to escape from the building they were in after a fire on Sunday morning.
Jersey Fire and Rescue Service said: "The occupiers were alerted to the fire by the smoke alarm which undoubtedly saved their lives."
The incident happened in a domestic property attached to a warehouse in Bellozanne Valley at about 01:00 GMT.
It is believed to have started in an airing cupboard, the fire service said.
On arrival there were "large amounts of smoke coming out of the properties doors and windows", it added.
Two fire engines with nine firefighters attended, and four entered the property wearing breathing apparatus.
The fire was put out before it could spread to neighbouring properties.