The deadly fire at One Meridian Plaza took place on February 23, 1991, across from City Hall, where the Residences at the Ritz-Carlton now stands.
Firefighters David Holcombe, Phyllis McAllister and James Chappell lost their lives battling that blaze.
The cause of the fire was traced to rags soaked in linseed oil left by workers.
The fire started at 8:23 p.m. on that Saturday night in 1991.
Arriving firefighters were met by flames shooting from the 22nd floor. They were also met by a series of mechanical failures inside the 38-story building.
Elevators stopped, backup generators failed and a crucial internal water distribution system called a standpipe actually choked off water pressure.
"They had a complete failure of all the fire protection systems and the electricity to the building, which allowed the fire to spread unchecked," said then-Philadelphia Fire Commissioner Roger Ulshafer at the time of the fire. "We were at a disadvantage from the beginning."
Flames raced up to floors 23 and 24.
Officials said the three firefighters were disoriented by the smoke and died in the fire.
The next day, firefighters evacuated the building fearing it would collapse. The blaze continued to burn until it reached the 30th floor, where sprinklers finally helped stop the spreading flames.
The fire burned for 19 hours.
Fire officials said one of the biggest lessons learned was the importance of sprinkler systems, which the City of Philadelphia later required in all commercial high-rises.
"There's no fire department in the world that can control a major fire in a high-rise building in an upper floor if the fire protection systems and also the redundancies that are built into them all fail," said Ulshafer in 1991. "Everything failed very early."
The Meridian was completely dismantled in 1999.
A memorial to the lost firefighters stands outside the Residences at the Ritz-Carlton.