Officers have arrested two people on suspicion of dangerous driving (credit: Essex Police)
A light blue Mazda 3TS collided with a blue Ford Focus in Brentwood Road at around 5.45pm on Tuesday, 28 January.
One person in the Focus suffered potentially life-threatening injuries.
Two others in the same car have been arrested on suspicion of dangerous driving and taken to hospital for treatment.
The driver of the Mazda has also been taken to hospital for care.
Officers closed the road for a few hours to investigate the circumstances around the collision.
They would like to speak to anyone who saw what happened, has any CCTV or dash cam footage, or has any other information.
You can contact police by calling 101 quoting incident 897 of 28 January.
Alternatively, you can contact Crimestoppers anonymously on 0800 555 111.Tags: Grays, Thurrock, Chadwell St Mary
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