A gas tanker truck exploded under a Mexico City highway overpass Wednesday, killing three people and injuring 70 others in one of the capital’s deadliest roadway accidents in years.

The tanker, which was carrying more than 13,000 gallons of gasoline, tipped over and erupted in flames that engulfed nearly 30 vehicles, sending thick smoke billowing across the city’s south side.

Mayor Clara Brugada said at least 19 of the injured were in critical condition, including children as young as two, while eyewitnesses described burn victims fleeing the inferno with clothing fused to their skin.

Authorities identified the truck with markings from the energy company Silza, though the firm denied ownership, and later the environmental ministry revealed the company lacked valid insurance paperwork for fuel transport, ABC News has reported.

President Claudia Sheinbaum expressed condolences to victims’ families and praised rescue workers, while officials confirmed the fire was extinguished and the highway to Puebla fully reopened by evening.