Tape recorded emergency calls from the first moments after last week's massive gas leak explosion in San Bruno, Calif., were posted today as residents returned to see what damage the blast had wrought on their homes and lives.
Some of the first reports came from commercial pilots flying over San Francisco International Airport nearby.
"There is one big fire that just started," one pilot says.
"Yeah, I know. We were just looking at that. That is huge," says another.
For nearly an hour, crews on the scene operated under the assumption that a commercial airliner had crashed into a neighborhood. "There's a plane down," says one dispatcher. "We're getting multiple responses started."
"Call for a fourth alarm. ... Appears we have a plane down in the neighborhood, multiple structures on fire and we have a fireball still coming out," says another.
Because of a broken water main, firefighters had to wait 10 minutes as hoses were attached to working hydrants where supplemental water was being trucked in.
An hour after the explosion, crews realized there was no plane crash. "It appears this is some sort of natural gas explosion," a firefighter says.
Home Video Reveals the Horror
A new home video has surfaced showing the horror residents saw.
In the video, one homeowner close to the explosion struggles to control the camera --and his emotions -- as orange and yellow flames fill the sky, and keeps even less control over his visceral reaction to the blast.
"What the f*** happened," homeowner Walter McCaffrey can be heard screaming. McCaffrey later said he shot the video from the deck outside his kitchen.
"To be honest, I was not thinking," McCaffrey told "Good Morning America." "I was just making sure my neighbors were -- I could see my neighbors running up the hill. And I was just running around the house, making sure everybody was out."
The explosion on Sept. 9 instantly leveled a neighborhood and killed at least four people. More than 50 others were injured.
Temperatures from the fire were so extreme that as the first fire truck got to the scene, its windshield cracked and firemen saw paint bubbling up on cars, one fire official said.
"It was like, picture a hot air balloon of fire. That big and high," witness Larry Fioranelli said Thursday. "The heat shot up the street and into the garage... It's like a movie when you see the A-bomb explosion... You felt the concussion."
Homeowners of more than 80 damaged homes were given police-escorted tours of their houses Monday, but were not allowed inside.
"Everyone's just looking for the little bit that they can identify, you know, out of really nothing," one resident said.
A ruptured natural gas pipe is believed to be the source of the explosion and has been shipped to a lab in Washington for testing to see why it burst.
"That's one of the things the metallurgy examination will help ascertain, because we'll be able to determine was the failure in the pipeline due to fatigue or was it because of an impact in the case of construction," Christopher Hart of the NTSB said Sunday.
At a packed community meeting overnight, frustrated residents looked for answers.
"The kids are traumatized. My wife's a nervous wreck. I'm just taking it day by day," one resident said. "It's a big time inconvenience, not just rebuilding the neighborhood. It's not something that's going to happen overnight."
Officials Look for Explosion's Cause
California regulators said Sunday they will order Pacific Gas and Electric -- the company that owns the ruptured pipe -- to survey all its natural gas lines in the state.
As part of the order from the state's Public Utilities Commission, PG&E must run leak surveys on all natural gas lines, with priority given to higher pressure pipelines and to lines in areas of high population density.
The commission also plans to appoint an independent expert panel to help with its investigation.
The pipeline was known to be potentially dangerous. In a 2007 document, PG&E, which owns the line, said the pipeline, "ranks in the top 100 highest risk line sections," adding that the "risk of failure at this location is unacceptably high."
The document was part of a budget request to replace the line.
San Bruno's mayor said he was unaware of the risk assessment.
"The whole thing is troubling to me," Mayor Jim Ruane said.
Investigators from the National Transportation Safety Board took measurements and pictures of pieces of the pipe that exploded, which is the focus of their investigation.
Sunday, the San Mateo County Coroner's Office released the names of three of the at least four people who were killed: Jacqueline Greig, 44, a California Public Utilities Commission employee; her 13-year-old daughter, Janessa Grieg; and 20-year-old Jessica Morales.
The name of the fourth victim has not yet been released, but Faye Wharton told ABC San Francisco station KGO-TV that the body of her 80-year-old grandmother was found in the ruins of her home, which is right next to the explosion.
Wharton told KGO-TV that she received word from authorities late Friday night. She said her two aunts and uncle, who were also in the house, made it out alive, but were severely burned.
Officials Probing Cause of San Bruno Pipeline Explosion
Local news reports said residents had attempted to alert Pacific Gas and Electric, the company that operates the pipelines, to the smell of gas days before the explosion.
"We have records that we are going back through right this minute to try and confirm what those phone calls looked like and when they occurred," PG&E president Chris Johns said Friday. Johns said that company policy was to immediately respond if someone calls in with a complaint about the smell of gas.
"We're really saddened and sorry about this tragedy," he said.
Officials from the National Transportation Safety Board are investigating the cause of the blast and will work with PG&E to determine exactly what happened.
"I want to make sure everybody knows that we are committed to do what's right and what's appropriate to help all the families and others who have been impacted by this tragedy," Johns said.
Johns said that no PG&E crews were working in the vicinity during the explosion, but he did not know about any other construction going on. The pipe that ruptured, Johns estimated, was 40 or 50 years old.
ABC affiliate KGO-TV and ABC News' Ariane Nalty, Neal Karlinsky and The Associated Press contributed to this report.