Around 60 e-bikes and batteries were stored in a garage where a fierce fire broke out at South Murwillumbah early Monday morning.

Four residents escaped the Railway Street property after a working smoke alarm sounded and one occupant alerted the others.

Fire and Rescue NSW crews were called just after 3am, with initial reports indicating the garage and adjoining house were alight.

Firefighters spent more than three hours bringing the blaze under control and preventing it from spreading to neighbouring properties.

The fire caused part of the house to collapse, while one resident was taken to hospital by NSW Ambulance.

FRNSW said the blaze was believed to have started in the garage, where around 60 e-bikes and batteries were being stored, although the exact origin and cause remain under investigation.

The incident has prompted another warning about the potential fire dangers associated with lithium-ion batteries.

FRNSW is urging people to use only approved chargers, avoid charging e-bikes or other lithium-ion devices while sleeping, disconnect batteries once fully charged and, where possible, charge e-bikes and e-scooters outside the home away from combustible materials.

Residents are also being reminded to regularly test smoke alarms and have a home escape plan.

Photo: Seven News