(Chris Post ~ Express-Times)
The victims ranged in age from 4 months to 79 years old, fire chief Robert Scheirer said, but city officials have not released the names of those killed or missing.
A couple in their 70s lived in a two-story row house that blew up about 10:45 p.m. Wednesday, police Chief Roger MacClean said. Michelle Hall told The Morning Call newspaper that her in-laws, Beatrice Hall, 74, and William, 79, lived in the home.
A neighbor, Dorothy Yanett, called them "a beautiful couple" who were active in the Methodist church and a local food bank. "Just lovely people."
Scheirer said 47 buildings were damaged, and eight were expected to be total losses.
The cause of the explosion was unclear. The state Public Utility Commission is investigating and looking for any violations of state or federal law, said agency spokeswoman Jennifer Kocher.
"We don't know if it was the main, we don't know if it was the service line, if it was inside the house, outside the house," Kocher said. "It's all very preliminary at this point."
The blaze was put out early Thursday, delayed by the difficulty of digging through packed layers of snow and ice to a ruptured underground gas line that was feeding the flames, Scheirer said. About 500 to 600 people who were evacuated were allowed to return home.
Yanett, 65, has lived on the block for nearly 40 years. She was in her living room with her husband awaiting the evening news when she heard a series of booms, she said.
"I couldn't tell where it was coming from," she said. "Everything falling and crashing, glass, just a nightmare."
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."
Residents of block are close-knit, she said.
"I can never go back here again," she said, choking up. "Too many memories."
The day before the explosion, a routine leak-detection check of the gas main that serves the area found no problems, said Joe Swope of Reading-based UGI Utilities Inc. The main dates to 1928.
There's no history of leaks for that section of 12-inch cast-iron main, and there were no calls about gas odors before the explosion, said Swope.
Utility crews had worked to shut off the gas mains in the area. The type of main used in that area typically do not have valves that allow for simply shutting off the stream of gas, a spokesman for the utility said in an e-mail.
The utility used foam to seal the gas main on both ends of a one-block area at about 3:45 a.m. Thursday. It took crews some time to cut through reinforced concrete underneath the pavement, Swope said.
The blast was so powerful that it sent a flat-screen computer monitor sailing into the back of Antonio Arroyo, whose house was on the opposite end of the row from the explosion.
"I thought we were under attack," he recalled from a shelter where some 250 people took refuge in the hours after the blast.
Arroyo and his wife, Jill, both 43, lost their home in the fire.
Antonio said he ran outside and saw that an entire house had been leveled, a fireball now raging in the spot where it once stood.
"What I saw, I couldn't believe," said Arroyo, a community volunteer.
He and his wife, a nurse, fled their home with only the clothes on their back. They planned to return at daylight to see what they could salvage. Jill Arroyo broke down sobbing when she recalled her son's athletic memorabilia -- likely lost in the blaze -- including DVDs of his high school football games.
"The DVDs are gone. All his trophies are gone. All gone," she sobbed as her husband comforted her.
Tricia Aleski, who lives a few blocks away, said the explosion jangled her nerves.
"I was reading a book in the living room and it felt like a giant kicked the house. It all shook. Everything shook," she said. "I checked the stove and everything, (to) make sure everything's off."
Jason Soke was watching college basketball when he heard and felt the explosion. It 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."
Last month in Philadelphia, a gas main explosion caught on video sent a 50-foot fireball into the sky, killing a utility worker, injuring six people and forcing dozens from their homes. Fire officials were investigating that blast.
And last September, eight were killed, dozens injured and 55 homes left uninhabitable when a gas pipeline in California exploded.
Late Thursday morning in Allentown, backhoe operators worked in the bitter cold to excavate the rubble from the explosion. Plywood covered more than a dozen blown-out windows at a church down the street; workers were boarding up the plate-glass front of the Arthritis Foundation building on the same block.
Lucina Santini and her husband, Jose, came to the scene Thursday morning. They live several blocks away and had heard the explosion.
"I really thought it was snow falling from the roof," said Jose Santini, 51. "It wasn't normal."