CHICAGO (CBS) — Four people were seriously injured Tuesday when a minivan slammed into a concrete wall on the Dan Ryan Expressway.

The incident happened on the Chinatown feeder ramp to the expressway near Cermak Road. The minivan was traveling in the left lane when for unknown reasons, it veered off and hit the barrier wall —where it caught fire.

Illinois State Troopers jumped out of their cruisers to help fight the fire.

Four people got out of the minivan alive. Police pulled a passenger out of the front seat, while firefighters rescued the driver.

The rear passengers were able to get out on their own.

CBS 2 is told all four people in the minivan were seriously hurt.

All lanes were shut down from 9 to 10 a.m.