Buffalo firefighters continue to investigate a difficult 4 alarm fire they battled well into the evening.

It all happened at Salerno Paint & Paper, 671 Wyoming Ave near Kensington ave, on the cities eastside.

The call came in about 3:40pm, Tuesday afternoon.

When firefighters arrived, they immediately called for a second alarm.

Smoke from the facility which houses volatile paints, solvents and chemical products was seen for miles, over the Eastside and could also be spotted as far away as the high-rises in downtown.

Shortly before 4:30pm, the building’s roof collapsed, leaving firefighters with no option but to fight from the outside.

As the fire was being fought defensively, crews poured water, hoping and waiting to extinguish the brutal flames. It flared up several times, each time sending plumes of thick, black smoke into the air.

With temps soaring above 80 degrees, it was a long and hot first day of Summer for the men and women fighting to contain the raging fire.

Almost half a dozen firefighters were taken to ECMC, treated for heat exhaustion and smoke inhalation. They are expected to be ok.

At 7:02pm, it was announced by fire officials that the blaze was finally under control.

WBLK has learned that Salerno Paint & Paper is not the only business that operates at this location. Call Associates Construction and Bentley Marble also does business at 671 Wyoming.

At this point, the structure is not a total loss, however Fire Commissioner Garnell W. Whitfield Jr. Says it "doesn’t look good".

There is no cause as of yet, however fire investigators say they’re looking into a blow torch that was being used by private contractors making repairs on the roof. Damage estimates to the structure have been placed at about $750,000.