Workers began removing the piece of cast iron pipe on Monday morning and finished just before 9 p.m., according to The Morning Call newspaper of Allentown. Another section had yet to be extricated.
Crews were taking their time because they don't want to lose any important evidence, said Joseph Swope, a spokesman for utility company UGI.
"It's a much longer process than it might typically take," Swope said. "It's a forensic investigation."
Gov. Tom Corbett, who visited the site Monday, said the explosion shows the state needs to think about its aging gas, water and sewer lines. But he noted tight state and federal budgets could limit any large-scale examination of infrastructure.
"The pipeline here, in Philadelphia, and everywhere in Pennsylvania is old, and we need to start to take a look at that," Corbett said.
The blast rocked an Allentown neighborhood Wednesday night, sparking an inferno that burned for hours while crews tried to shut off the supply of gas. A 16-year-old girl and a 4-month-old boy were among those killed.
The explosion flattened a pair of row houses and set fire to a block of homes in an area where the underground gas main lacked shut-off valves. Neighbors said the blast knocked shelves off walls, brought down ceilings and ripped a front door off its hinges.
Crews working at the site of the blaze uncovered the damaged portion of pipe on Sunday, UGI CEO John Walsh said. A visual inspection revealed a break that company officials believe was the source of the gas.
UGI crews conducting routine inspections in the area reported three other small gas leaks on Sunday. There was no residential evacuation, but The Morning Call reported that some residents opted to stay elsewhere.
On Monday, Swope said soil samples were being taken and other investigative work was being done during the pipe removal. He said the pipe will be taken to a forensic engineering firm in New Jersey for analysis.
Corbett said he planned to speak to the Pennsylvania Utility Commission this week. He noted it was premature to say whether the disaster qualified for state aid, but he said the state was ready to assist if needed.