231, built in 1929, of riveted seam construction, had a capacity of 75,000 barrels (11,900 m3) and had recently been renovated with an internal floating roof.

4 and this stack was a familiar sight to westbound motorists on the Penrose Avenue Bridge, as the word “GULF” was painted in large, white letters.

The initial explosion also damaged the pipe manifold outside of the dike wall and petroleum pouring out under pressure ignited.

The sixth alarm was ordered by Fire Commissioner Joseph Rizzo at 6:52 a.m. Over the next several hours, firefighters utilized deluge guns and master streams to cool down surrounding exposures, and applied foam directly to the burning tanks and piping in an effort to extinguish the fire.

Commissioner Rizzo remained on the firegrounds throughout the warm, muggy August day to continue to oversee the firefighting operation.

Additional foam was acquired throughout the day from the fire department's warehouse and the nearby Atlantic Richfield refinery.

However, as the firefighting operation progressed, it became apparent that the refinery's sewage system was not up to the task of properly draining the foam, water and petroleum-naphtha product mixture that was accumulating on the ground along Avenue Y, between 4th Street and 5th Street to the east, running in front of the refinery's administration building.

These pumps were shut off as part of a decision to de-energize overhead power lines that ran adjacent to Tank 231 along 4th Street.

Commissioner Rizzo and Gulf Refinery manager Jack Burk were on an overhead catwalk nearby observing the fire-fighting operation.

Viewing the unfolding horror before him, Commissioner Rizzo ordered the seventh and eighth alarms, five additional rescue squads, and the recall of all companies which had previously been released from the firegrounds throughout the day.

The burned firefighters were loaded into the Gulf Refinery Ambulance which roared past Rescue 7 – a mobile intensive care squad and the first apparatus to arrive on the scene after the liquid reignited.

The apparatus was moved to the road East of the expressway and found the Gulf Fire chief on the ground suffering from a heart attack.

At 4:46 p.m., Commissioner Rizzo ordered the ninth alarm and notification of Philadelphia Managing Director Hillel Levinson as a major disaster was now unfolding at the Gulf Refinery.

At 5th Street, where Engines 16 and 40 had been assigned to improve drainage, their pieces were also destroyed in the fire's path, although their pump operators were able to escape.

At 5:37 p.m., Commissioner Rizzo ordered the tenth alarm as the fire was then traveling southward and engulfing the refinery's administration building, which was located on the south side of Avenue “Y” between 4th and 5th Streets.

The tenth alarm companies were ordered to report to Gate 24 at Penrose and Lanier Avenues, to set up deluge guns then remove themselves from the area.

The second alarm was ordered at 6:07 p.m., followed by a special call for three additional engine companies at 7:18 p.m. Assistant Fire Chief James Skala, who had been at the New Jersey shore, returned to the city and assumed command of operations.

By 7 a.m., the involved tanks and pipelines were gushing flames and nearby streets in the complex were burning streams of oil and other petroleum products.

At 1 a.m. on Monday, August 18, 1975, Commissioner Rizzo left the firegrounds, going to area hospitals to visit the injured firefighters and to the homes of the families of the members who were unaccounted for.

To curtail this fire, it was determined that the valve, hidden behind an earthen levee at the rear of the tank, about 100 feet (30 m) from the burning naphtha, needed to be closed.

However, in the intervening week, box alarms were transmitted for “flare-ups” on four occasions to assist the fireground details that continued to work on the fire.

Thirty-nine charges were reportedly dismissed by judge Earl Simmons Jr.[19][20] [21] In August 2007, about 200 people gathered at the Fireman's Hall Museum in Philadelphia as International Association of Fire Fighters President Harold Shaitberger unveiled individual plaques honoring the firefighters lost in the refinery disaster.