Two adults and two children were taken to hospital on Wednesday evening after a fire broke out in the basement of a home in St Helier.
Emergency services received "multiple calls" at about 19:50 GMT, with three fire engines sent to tackle the fire which started in an electrical cupboard.
Smoke was found to have risen into several flats in the building, with one person being rescued from the top floor.
Jersey Fire and Rescue said the incident was a reminder of the importance of having a working smoke alarm within properties and shared hallways