An out-of-control tanker truck carrying thousands of gallons of gas crashed into a storefront and burst into flames in Rockville Centre early Wednesday.

Officials say the tanker crashed into a liquor store and then into a former La-Z-Boy furniture store around 1:15 a.m. at North Centre Avenue and Sunrise Highway.

Sources say the gasoline tanker was owned by Rocket Express of Bay Shore and was traveling eastbound.

Officers tell News 12 the driver of the tanker ran out and said another driver cut him off before he collapsed.

Three firefighters were hurt during the fire but were not seriously injured, the Village of Rockville Centre confirms. The driver of the tanker also suffered minor injuries.

"I've seen fires and I've seen them go out quick, but I've never seen a building collapse like that,” said Brett Agostini, of Rockville Centre.

Agostini was on his way home from work when he saw the former La-Z-Boy furniture store erupt in flames.

“It was a heavy, high volume of fire. Again, 9,200 gallons spilling. It was in the storm drains, causing explosions underground. It was quite a scene they had to handle when they first got here,” said Nassau County Fire Marshal Michael Uttaro.

First responders say that gasoline traveled a quarter of a mile into the storm drains and caused manhole covers to explode early Wednesday.

Officials say that was a result of the spill, which has been contained.

Nassau County fire marshals say the gasoline made its way down into the Mill River. Cleanup crews are placing booms, an oil absorbent, to soak up the gasoline on the water's surface.

The U.S. Coast Guard was brought in to map the migration of the gasoline and any damage.

The county says there is no threat to the environment or residents.

The state Department of Environmental Conservation is overseeing the environmental cleanup.

As a precaution, a large area in the heart of Rockville Centre has been closed down and will remain closed until at least Wednesday evening.

Officials say before they can open the stretch of Sunrise Highway again, crews must excavate the building area to make sure all hot spots are out. Then the state Department of Transportation will come in and do their own safety assessment before any green light can be given.

Some of that burning fuel made its way into storm drains — and the nearby Mill River — posing serious environmental concerns.

“The contamination apparently is under control,” says Nassau County Executive Bruce Blakeman. “We have the DEC there. The United States Coast Guard mapped out the area so we have a good handle on cleaning the sewers and making sure we contain any of the gasoline that may have run through the sewers into streams and the pond.”

Nearby schools and businesses that were shut down should be operating by Thursday.

Blakeman's office tells News 12 that the county expects all lanes on both Sunrise Highway and Merrick Road near the accident scene to be reopened for the early commute.

“We’re anticipating tomorrow to be a normal day,” Blakeman says.

"At my direction, multiple State agencies, including the Department of Environmental Conservation, Department of Transportation, Division of Homeland Security & Emergency Services and New York State Police responded overnight to an incident in Rockville Centre, where a tanker truck crashed into a building along State Route 27 (Sunrise Highway). The crash resulted in a fire and an estimated 9,000 gallons of fuel spilled. The scene remains active with Route 27 and its surrounding roadways closed. Motorists and pedestrians should avoid the area. At this time, State agency personnel continue to support Nassau County's response to the incident. DEC has deployed Environmental Conservation Police Officers and Spill Responders, including a drone pilot, to assess the potential environmental impacts to the Mill River and surrounding area and to pump out, clean, and flush the impacted drainage system. DOT is currently assessing damage to the drainage system, pavement and a traffic signal and additional information will be provided as it becomes available," says Hochul.

Investigators have not said what caused the tanker driver to lose control, but a member of Nassau’s Arson and Bomb squad told News 12 it appears in the surveillance video that he was cut off by another vehicle.