At least one person was killed after three rowhome buildings collapsed in an explosion in Philadelphia’s Nicetown-Tioga neighborhood early Sunday, sending at least two other people to hospitals, officials said.

Philadelphia police and fire units responded to the 1900 block of West Bristol Street, near Clarissa Street, just before 5 a.m. CBS News Philadelphia cameras in the area show at least three structures that have collapsed with smoke emanating from the rubble.

Officials said the two people taken to hospitals are an 82-year-old woman and a 62-year-old woman – one is in critical condition and the other is in stable condition.

“This will be an extensive, all-day operation for the Philadelphia Fire Department,” Philadelphia Fire Department executive officer Daniel McCarty said.

McCarty said other buildings adjacent to the collapse have damage as well. Some residents have been evacuated as a precaution in case other collapses occur. Officials are monitoring the buildings there in case any still standing show signs they may collapse.

The cause of the explosion is under investigation and search and rescue operations are underway. The Philadelphia Department of Licenses and Inspections is on site examining buildings. Several workers from Philadelphia Gas Works were also seen on the block.

McCarty said investigators will work “brick by brick” to find out what happened.

The Bureau of Alcohol, Tobacco, Firearms and Explosives is also on the scene.

Neighbors told to evacuate Bristol Street after collapse

Around 9 a.m. residents were exiting their homes on Bristol Street after being told to evacuate. Many were holding suitcases or shopping bags full of personal effects.

All along the block, homes have broken windows and some doors were blown off the hinges. Vehicles parked on the street also suffered damage from the blast and from debris.

A spokesperson for The American Red Cross says it responding and will work with residents who need assistance.

“Big bang” wakes up residents

A resident on the block said she was sleeping when she heard “a big bang” and at first thought her husband fell off the edge of the bed.

“And then I had to come to the window and look out, and I seen people walking up and down the street,” she said. “And then I came downstairs and my door was all blown open and there was glass everywhere on my floor.”

Other residents from blocks away felt their houses shake. Another resident said he heard a noise that sounded like thunder.

“I mean, it’s like something out of a movie. The houses, you know, they’re underneath. So they had to pull them out of the house,” one woman said.

This is a developing story and will be updated.