ALLENTOWN, Pa. — A thunderous gas explosion devastated a rowhouse neighborhood, killing five people, and suspicion fell on an 83-year-old cast-iron gas main. The fiery blast was latest natural-gas disaster to raise questions about the safety of the nation's aging, 2.5-million-mile network of gas and liquid pipelines.
The explosion, which flattened a pair of rowhouses and set fire to a block of homes late Wednesday night, occurred in an area where the underground gas main lacked shut-off valves. It took utility workers five hours of toil in the freezing cold to punch through ice, asphalt and concrete and seal the 12-inch main with foam, finally cutting off the flow of gas that fed the raging flames.
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An elderly couple who lived in the home died. They were identified by their daughter-in-law as Beatrice Hall, 74, and her husband, William, 79, the Allentown Morning Call newspaper reported on its website. The names of the others were not immediately released.
It took utility workers five hours of toil in the freezing cold to punch through the ice, the asphalt and a layer of reinforced concrete and seal the 12-inch main with foam, finally cutting off the flow of gas that fed the raging flames.
Images from NBC station WCAU showed flames reaching hundreds of the feet into the air from the scene of the blast. The explosion was so powerful it was felt nine miles away in Bethlehem, Pa.
Dorothy Yanett, 65, said was in her living room with her husband awaiting the evening news when she heard a series of booms.Video: Gas blast demolishes houses in Pennsylvania
"Everything falling and crashing, glass, just a nightmare," said. She found glass in the shoes she was going to put to leave the house. "There was no odor, there was no smell. Then it was like all hell broke loose."
Joe Swope, a spokesman for Reading-based UGI Utilities Inc., said that a routine leak-detection test in that area had come up clean on Tuesday, and that there had been no calls about gas odors before the disaster.
Forty-seven homes were damaged, and eight of them appeared to be a total loss, said Allentown Fire Chief Robert Scheirer.
The exact spot of the explosion and what triggered it were under investigation.
"The investigation will look at the 12-inch main, but will also look at service lines that feed gas into the nearby homes and businesses, as well as potential causes inside the home," Scheirer said. "Until that investigation is complete, it's premature to conclude exactly where the leak took place."
Investigators planned to send cameras through the main to look for cracks, and perform air pressure tests on the service lines.
Last September, a 44-year-old gas transmission line ruptured in San Bruno, Calif., killing eight people, injuring dozens and leaving 55 homes inhabitable. Investigators said the pipe had numerous flawed welds. And in Philadelphia last month, a gas main explosion sent a 50-foot fireball into the sky, killing a utility worker, injuring six people and forcing dozens from their homes. Fire officials are investigating.
Past pipeline explosions have been blamed on such factors as corrosion or damage done by heavy construction equipment.
Swope said there was no history of leaks in the immediate area. Asked about any plans to replace the main, the utility spokesman said that the section had been deemed safe and reliable. He also said there had been no recent construction in the neighborhood.
As for the possibility that the freezing weather caused a pipe to rupture, Swope said: "In the winter, there's always the concern about the freezing-thawing cycle, but seeing that we just ran the leak survey less than 48 hours before the incident, that doesn't appear to be a cause."
The blaze was too hot to allow workers to go to the curb or a home to cut off the gas, so they had to go into the street to plug up the main, according to the fire chief. Swope said shut-off valves are not considered feasible for that type of main construction, which dates to 1928.
An Associated Press investigation published Saturday found that many pipelines around the country are not equipped with remotely operated or automatic shut-off valves that can quickly stop the flow of gas in an accident, even though federal safety officials have recommended such devices to industry and regulators for decades.
Pennsylvania Public Utility Commission spokeswoman Jennifer Kocher said age is not the only consideration in deciding when to replace gas lines. Other factors include the number of leaks per mile, how the soil's composition could affect the pipe, whether it is located in a densely populated area, the amount of pressure and the size of the line. The gas main in that area was under comparatively low pressure, she said.
Antonio Arroyo said he and his wife fled their home with only the clothes on their backs. Their home was considered a total loss.
"I thought we were under attack," he said in a shelter with about 250 other evacuees a few hours after the explosion.
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Another onlooker near the scene of the fire, Leonard Hein, said the blast sounded like a military rocket.
"I thought I was back in Vietnam," he told the Morning Call.
Dale Dalrymple told the Lehigh Valley Express-Times that he lives directly across the street from the destroyed home.
"I was in the basement watching a movie with my granddaughter," Dalrymple said. "All I felt was like a suction and a big boom and I ran upstairs and here my front door was blown open."
After fleeing his house in temperatures below freezing he said he saw flames coming from the second story of the row home that had been attached to the destroyed home.
"The house is not even there. It's gone," he told the Express-Times.
On Thursday, backhoes dug into the rubble in the devastated neighborhood and plywood covered blown-out windows of a church.
"I was reading a book in the living room and it felt like a giant kicked the house. It all shook. Everything shook," said Tricia Aleski, who lives a few blocks away. "I checked the stove and everything, make sure everything's off."
Jason Soke was watching college basketball when the explosion rattled his windows. He went to the third floor and looked out and saw flames and smoke.
"Your senses kind of get stunned," he said. "It puts you on edge."
The Associated Press contributed to this report.