On Wednesday afternoon, September 10th, a gas tanker truck overturned in the Iztapalapa neighborhood of Mexico City, sparking a huge explosion under a highway bridge.

What happened: The truck rolled over beneath the overpass, causing a gas leak. The fuel spilled and quickly ignited, leading to a fireball and heavy blast that damaged dozens of vehicles nearby.

• Four people died from the explosion.
• About 90 people were hurt, many with serious burns. Some victims are in critical condition.
• The truck driver survived but was badly injured.

The response: Local firefighters had to battle the blaze for hours before it was safe to clear the scene. Emergency crews tried to help the wounded and secure the area as fast as possible.

Company update: Transportadora Silza, the trucking company involved, first denied responsibility but later said it would take the matter seriously. Officials noted Silza did not have proper insurance to haul gas at the time of the crash, according to the New York Times.

The investigation is ongoing. No other updates have been released on what caused the truck to overturn.