An early morning house fire in Hempstead spread to two neighboring homes.

Flames broke out on Oak Avenue around 1 a.m., fire officials say.

The first home appears to be vacant and under construction, according to the Nassau County Fire Marshal’s Office.

Eighteen total people are displaced after the blaze spread to the two additional houses. The original affected home sustained significant damage, while the others suffered moderate damage.

Officials tell News 12 about 75 firefighters from multiple departments responded to the scene.

One firefighter was treated at the scene for a hand injury.

The cause is still under investigation by the fire marshal's office and the Nassau County Police Department Arson/Bomb Squad.