A major fire started around 7pm at a recycling plant in Greenpoint last night, and raged on for hours before the FDNY managed to get it under control. NY1 reports that it took 150 firefighters most of the night to put out the fire, which at its worst was labeled a Four Alarm blaze. The flames were reportedly doused by 6am this morning, though one Twitter user snapped a picture of authorities continuing to spray water on the site.

“It was a very, very fast-moving fire with extremely flammable contents,” Deputy Fire Chief Robert Strong told NY1. “Fortunately this is an industrial area.” Of course, all the paper products on-site seem to have acted as kindling, and Strong explained, “We had large bales of cardboard strapped with steel straps and we had rags throughout, so getting to the very seat of all this smoldering cardboard and rags was very difficult,” he said. “It’s a very time-consuming process.”

The fire also rendered the building unstable enough that firemen were unable to enter, slowing down the process (at one point parts of walls were apparently collapsing). Miraculously, other than minor injuries to four firefighters, no one seems to have gotten seriously hurt here, and none of the adjoining buildings were damaged. No word on what actually caused this, but in any case, it’s a relief that it’s over.

Follow Virginia K. Smith on Twitter @vksmith.