Updated: March 14, 5:05 a.m. E.T.
Firefighters pulled an eighth body from the rubble Thursday as the death toll continued to rise from Wednesday's gas explosion in New York City.
City officials say a gas leak triggered the explosion Wednesday morning, which injured more than 60 people and leveled two buildings in upper Manhattan. At least three of the injured were children, the Associated Press reports.
Rescue workers spent a wet, frigid night searching for victims buried under the rubble, using floodlights and thermal-imaging cameras to identify heat spots that might indicate bodies. Police in surgical masks guarded the site as temperatures dropped into the 20s, according to the AP.
Mayor Bill de Blasio said at a press conference Thursday afternoon that firefighters are still putting out smoldering fires in the wreckage and said the city is "continuing rescue operations hoping to find others still alive."
He said 66 people are receiving temporary shelter at the Salvation Army.
Rescue crews had cleared away roughly half of the debris by Thursday evening, hoping that at the current rate they might reach the building's foundation by Saturday. In the meantime, they are sifting through each layer of rubble for human remains and clues to the cause of the explosion.
The New York City fire and police departments will jointly investigate the explosion in collaboration with the National Transportation Safety Board (NTSB), which investigates pipeline accidents, the mayor said.
An NTSB investigator told the AP they would conduct a timeline of events and look into how the Con Edison utility handled reports of gas odors.
Residents of one of the buildings told the New York Times they smelled gas Tuesday night and the odor was still noticeable Wednesday morning.
A Con Ed spokeswoman confirmed that the utility received a call about a heavy gas odor at 9:13 a.m., less than 20 minutes before the explosion. A Con Ed crew dispatched two minutes after the call arrived just after the explosion.
The New York City fire department said it had no reports from tenants of gas leaks in the past month.