A fire that broke out at the Pearl River indoor shooting range on Sunday is finally out, officials say.

Fire officials say the flames began around noon inside the Rockland Indoor Shooting Education gun range, also known as RISE, in the Pearl River Shopping Center. Firefighters finally got the flames under control around 4 a.m. today.

According to fire officials, the flames started somewhere in the shooting range, which is located in the basement of the building on busy North Middletown Road.

On top of the shooting range is a Dollar General and a Dunkin’.

Pearl River Fire Chief James Morrison says the problem is that the fire was inside the walls and running the length of the building,making it difficult for crews to get to the fire. "Every time we open one space, there's another space we find. So, there's a cockloft that basically runs the length of the gun range down there, the long gun range and the short gun range that we basically got into, but it goes even further than that - so it's just an ongoing thing."

Morrison says they found a lot of void spaces and had trouble reaching the fire itself. "We cut the floor, we did all sorts of stuff. We brought in high expansion foam, all sorts of things to no avail, nothing worked."

The last option was to give the fire oxygen to bring out the flames, and that did the trick.

More than 100 firefighters from at least 23 fire departments around the region responded, with some coming in from Westchester and New Jersey. At least six firefighters were taken to the hospital with minor injuries and are expected to OK.

But it wasn't just the fire that crews had to worry about, there were also tens of thousands of rounds of ammunition inside the shooting range and enough heat to make tthe rounds explode. "A lot of it was popping off. So we went to an exterior attack, we didn't want to put anyone in the building. And we could hear the rounds from up here, but we kept everyone away and safe," says Morrison.

The shooting range, Dollar General and Dunkin' are destroyed, but the other business suffered just light smoke damage.

There is still no word on the cause of the fire.