In East Palestine, Ohio, about 2,000 residents -- approximately half the town's population -- have been ordered to evacuate their homes after a Norfolk Southern train derailed and caught fire.

Gov. Mike DeWine urged all residents living within a mile of the derailment to evacuate "immediately" Sunday night "due to the potential of a major explosion."

The train, traveling from Illinois to Pennsylvania, derailed around 9 p.m. Friday, ignited and prompted a response from more than 50 fire departments across three states, according to East Palestine Mayor Trent Conaway.

Janet Meek, who lives about one block from the railroad tracks, said she heard a "loud boom" around 9 p.m. Friday. Her husband reported seeing a "billowing ball of fire" while walking their dogs.

The National Transportation Safety Board said Sunday that two videos show preliminary indications of mechanical issues on one of the rail car's axle. The train's emergency brake was activated after crews said an alarm went off, according to the NTSB. There were no injuries, the agency said.

Conaway told ABC News on Saturday that residents living in a one-mile radius of the fire were asked to evacuate or shelter in place voluntarily.

Meek, a 55-year-old resident in the evacuation zone, said she decided not to evacuate due to concerns about her pets, though she reported feeling the impacts of the blaze when she went outside.

"It's like burning our eyes, and it was burning our throats," she said. "We don't ... didn't feel real good."

Fire chief Keith Drabick told reporters Saturday that the train was carrying hazardous substances but could not confirm if the fire impacted the train cars carrying the hazardous goods. Drabick said the odor permeating East Palestine is not harmful at current levels, but representatives from the Environmental Protection Agency are monitoring the situation.

East Palestine is a small village on the border of Pennsylvania and Ohio with roughly 4,700 residents.

A spokesperson from Norfolk Southern said they are "coordinating closely with local first responders while mobilizing our own teams."

Efforts to contain the fire stalled Saturday night when firefighters withdrew from the blaze due to concerns about air quality and explosions.

Conaway said firefighters withdrew from the fire Friday night due to concerns about air quality, with a plan to reengage once they get a "better grasp of what exactly is what chemical is burning." At Saturday's press conference, Drabick said there had been multiple explosions overnight, which posed a risk to firefighters.

ABC News' Darren Reynolds contributed to this report.