A man takes photos as a black plume rises over East Palestine as a result of a controlled detonation of a portion of the derailed Norfolk Southern trains Monday. (AP Photo/Gene J. Puskar)

EAST PALESTINE (AP) — Air monitoring hasn’t detected dangerous levels of fumes in communities where crews released and burned toxic chemicals from a derailed train, but Ohio and Pennsylvania residents living close to the wreckage still aren’t being allowed in their homes, authorities said today.

While the fire from Monday’s controlled release of the chemicals was no longer burning, authorities said they want to ensure the air is safe before lifting the evacuation order.

“I want nothing more than to get my residents back home,” said East Palestine Fire Chief Keith Drabik. “Safety is paramount.”

Residents on the edge of the village, close to the Pennsylvania line, were ordered to leave because of the risk of death or serious injury from toxic fumes produced by the release and burning of vinyl chloride from five derailed tanker cars that had been in danger of exploding.

About 50 cars, including 10 carrying hazardous materials, derailed in a fiery crash Friday night while traveling from Madison, Illinois, to Conway, Pennsylvania, according to Norfolk Southern and the National Transportation Safety Board.

Crews from the U.S. Environmental Protection Agency and the Ohio National Guard are now monitoring samples from around the area. National Guard members wearing protective gear were being deployed to take readings inside homes and businesses, said Major General John Harris Jr.

Those living just outside the evacuation zone in East Palestine and in neighboring Beaver County, Pennsylvania, were urged to stay indoors as a precaution.

So far, no injuries have been reported from the derailment or the controlled release but some residents have complained about smelling chlorine and smoke in the air and having headaches.

Most, if not all, residents in the danger zone left well before the chemicals were released and burned and authorities went through the area three times trying to get people out, Ohio Gov. Mike DeWine said.

Officials warned the controlled burn would send phosgene and hydrogen chloride into the air. Phosgene is a highly toxic gas that can cause vomiting and breathing trouble and was used as a weapon in World War I.

Releasing the chemicals during the daytime allowed the fumes to disperse more quickly and prevented the rail cars from exploding and sending shrapnel and other debris flying through the neighborhood, said Scott Deutsch, of rail operator Norfolk Southern Railway.

The process involved using a small charge to blow a hole in the cars, allowing the material to go into a trench and burning it off before it’s released in the air, he said.

The site of the derailment is very close to the state line, and the evacuation area extended into a sparsely populated area of Pennsylvania. About half of the 4,800 residents of East Palestine had been warned to leave over the weekend before officials decided Monday to use the controlled release.

Federal investigators say a mechanical issue with a rail car axle caused the derailment.

Forced evacuations began Sunday night after authorities became alarmed the rail cars could explode after a “drastic temperature change” was observed in one car.