By CBS3 Staff

PHILADELPHIA (CBS) — Philadelphia Fire Commissioner Adam Thiel was emotional at a press conference on Saturday after a city firefighter was killed and five other people were injured after a building collapsed in Fairhill. Fifty one year-old Lieutenant Sean Williamson died in the building collapse after he was trapped in the rubble.  

Thiel said the collapse on West Indiana Avenue is the latest incident in what has been a tragic year for the Philadelphia Fire Department. 

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“Because of the degree of the collapse and where Lieutenant Williamson was located in the structure, we were not able to save him,” Thiel said. “And believe me, for our members, this is just another tragic event in a very tragic year.”

Philadelphia Fire Commissioner Adam Thiel Reacts To Building Collapse That Killed City Firefighter: 'I’m Almost Speechless'

Earlier in 2022, a house fire in Fairmount killed 12 people, including nine children. It was the deadliest single fire in Philadelphia in at least a century.

In April, a father and his three sons died due to a house fire in Kensington. The mother of the boy’s survived after she was pushed out the window of the home by her partner. 

“The worst thing for any firefighter or any medic, we all swear to save lives and protect property, and any time we can’t do that – whether it’s a resident of the city and certainly if it’s one of our own sisters and brothers, we feel it very deeply,” Thiel said. “This has been a tragic year for the Philadelphia Fire Department. We’re just absolutely devastated.”

Williamson, a 27-year veteran of the department and former Marine, was recently assigned to Ladder 18 in the city’s Hunting Park neighborhood. Black bunting is currently draped over the firehouse as his colleagues mourn his death and remember his service.

Paramedics pronounced him dead about 3 hours after the structure fell. 

Thiel said Williamson was one of the most experienced lieutenants in the department. He leaves behind his mother and son.

“I’m almost speechless,” Thiel said. “I’m not done crying but I’ve cried once already.”

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“Today is a heartbreaking day for our city,” Mayor Jim Kenney said. 

Five others were rescued from the rubble. 

Firefighters Robert Brennan Jr. and Dennis Daly are in critical but stable condition. Both are at Temple University Hospital. 

Lieutenants Sylvester Burton and Clarence Johnson were both treated and released from Temple. Inspector Thomas Rybakowski was also treated and released. 

“So they didn’t all make it out at once… there were different levels of when they came out,” Deputy Commissioner Craig Murphy said. “So the times may have been early on in the collapse, some came out, one person jumped from the second floor to avoid being caught in the collapse and then the other ones were systematically extracted and removed from the collapse.”

To honor Williamson’s legacy, Kenney said all city of Philadelphia flags will be flown at half staff for 30 days. 

“Tragically we’re no strangers to line of duty deaths, that doesn’t make it any easier,” Thiel said. “We’re absolutely grieving, we’re mourning, we have a lot more crying and a lot more processing to do as this unfolds and we’ll move forward by honoring Lieutenant Williamson.”

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CBS3’s Jasmine Payoute contributed to this report.