Pianos launched into the air when a "huge boom" rocked the East Harlem piano store where Colin Patterson works.
"The pianos flew off the ground and flew around me," said Patterson, a piano technician at Absolute Piano on the ground floor at 1646 Park Ave., one of two buildings leveled Wednesday morning by a massive explosion caused by a suspected gas leak.
Patterson, finding himself "in a miraculous cocoon" of debris after the blast, managed to dig himself out and crawl through a window, escaping with only a scratch on his left wrist.
"It was a huge boom, like a sonic jet engine. The building fell on top of me," said Patterson, who has lived on the building's ground floor for 10 years.
The 9:30 a.m. explosion, powerful enough for witnesses to mistake for an earthquake, could be heard across a large swath of upper Manhattan.
As the buildings crumbled, shards of glass and tons of bricks rained down on the busy street below. Parked cars were crushed, and railroad tracks nearby were covered with debris, shutting down rail service.
Frantic residents and workers rushed outside. Many saw the buildings fall, sparking a raging fire. A cloud of thick white smoke and dust filled the air, as scores of firefighters battled the blaze.
David Casareo, 35, a Bronx carpenter who was working a job across the street, said he and a colleague ran to the scene and began searching for victims.
"I was digging through the bricks and I saw a blanket," Casareo recalled. "I moved the blanket, and there was this kid.. . . He was bleeding a lot."
The victim, a boy between 7 and 10 years old, told the rescuers, "I have a lot of pain," Casareo said.
"We grabbed him and brought him to the cops. He kept asking for help. I told him, 'Don't worry. You'll be OK.'"
Casareo and co-worker Alex Camillo, 35, of Manhattan, also rescued two people from a minivan that had been partially crushed by falling debris.
"We pulled the people out of the window," Camillo said.
Gregory Garcia, 50, who has lived in the neighborhood his whole life, said the explosion "sounded like a bomb. My building shook. I felt a vibration through my body."
Carlos Perez, 60, was on the block working at a shop that sells medicinal herbs.
"When I heard the explosion, it broke all the windows and shattered glass onto my chest. I thought it was a train that might have derailed," he said. "I ran out to the corner and there was smoke everywhere."
He said cars stopped at a red light at 116th and Park were overturned -- flipped by the force of the blast.
Ruben Borrero, 32, who has lived at 1646 Park Ave. with his family for many years, heard about the explosion from a friend and rushed home to find his home in rubble.
"All I saw was an empty lot," he said at an American Red Cross shelter at PS 57 on Third Avenue and East 115 Street. "My life was in that building; my father's ashes and my family dog."
Borrero had left in the morning to drop his son off at the baby sitter. He said his family, who lived in the second floor, will now stay with other relatives.
"All we have is what we have on our backs," he said.
With Joan Gralla and Nicole Fuller