EL PASO, Texas (Border Report) – A 4-year-old child is dead, a woman has lost her foot, and firefighters were trying to contain a spill of sulfuric acid after a train carrying stowaway migrants left the tracks Tuesday night just south of Juarez, Mexico.

Twelve boxcars and tank cars lay on their sides near the tracks, surrounded by dozens of firefighters and Mexican National Guard troops keeping people away from the spill, authorities in the border state of Chihuahua said.

“We are maintaining safety measures due to the hazardous spill near the Juarez-Ahumada highway,” said Luis Corral Torresday, head of the Chihuahua Civil Protection Office. “In the early hours, a search was conducted for a missing child – as the accident involved (migrants), one from Nicaragua and four from Venezuela. First responders are reporting the child was found (Wednesday morning) with no signs of life.”

A 28-year-old woman’s foot was severed during the derailment and a 17-year-old male suffered serious head injuries. Both were taken by ambulance to a hospital in Juarez, the Civil Protection Office said.

The cause of the derailment is under investigation and the spill appears to involve a single tank car, authorities on the scene told Border Report news partner ProVideo.

Sulfuric acid is a corrosive fluid used in petroleum refining, metal processing and to make fertilizers. It can catch fire if it comes into contact with other chemicals and can emit toxic fumes if heated, according to the Centers for Disease Control and Prevention.

Migrants used to travel atop trains from southern Mexico to border communities like Juarez by the hundreds before the Mexican government cracked down on the practice last May.

A few migrants still manage to get on trains undetected to arrive at a border where asylum-seekers without an appointment at a U.S. port of entry are sent back or expeditiously removed because of a June 4 Biden administration executive order.