"My room shook, I was disoriented," Whitaker said. "Feels like an earthquake right in your room, an earthquake and a car crash right in your room, that's loud and abrasive. It was shaking, and I thought the Metro-North [train] had crashed."
The city Buildings Department has determined that the structural integrity of surrounding buildings was not impacted by the explosion and fire.
Officials investigating the cause of the explosion said the pipe that supplied natural gas to the two buildings has no obvious rupture, and that is not unusual for a low pressure type such as this one to remain intact.
A pressure test will be needed to determine the location of the leak, said Robert Sumwalt of the National Transportation Safety Board, which also investigates gas pipeline accidents.
Relatives still searching for their loved ones can call the city's 311 hotline and ask for the unified victim identification system, said de Blasio, confirming they had received roughly 200 calls so far.
"I want to emphasize anyone affected by this tragedy will be helped, regardless of immigration status," said de Blasio. "They should not be afraid. We intend to help everyone."
ABC News' Dan Childs contributed to this report.