The flames broke out just after midnight in the basement of a building on East Marie Street and was under control within two and a half hours.
No civilians were hurt but one firefighter suffered a minor injury and was treated at the scene.
It is not yet known how many businesses were affected or how badly they were damaged.
The cause of the fire is under investigation but the cause is not considered suspicious.
Officials say there was an active natural gas leak that was a result of the fire and was not the cause of the fire.
National Grid was on scene and had to identify the exterior valve and shut down the gas from the street.
----------
* More Long Island news
* Send us a news tip
* Download the abc7NY app for breaking news alerts
* Follow us on YouTube