Police were called to a two-car crash on London Road close to the Stonehouse Corner roundabout at around 10.15pm yesterday (April 24).
A 17-year-old boy died at the scene despite attempts to save him.
His family have been informed and are being helped by specially trained officers while the investigation is carried out.
An 18-year-old boy from Rainham was arrested on suspicion of causing death by dangerous driving and is in custody.
The road was closed overnight and has since reopened.
An Essex Police spokesman said: “We are now appealing for any drivers in the area at the time of the collision to get in touch, in particular with dashcam footage, to support our enquiries.
“You can let us know by submitting a report on our website or by using our online Live Chat service which is available 24 hours-a-day, seven days-a-week.
“It can be found at the bottom right of our homepage at www.essex.police.uk.
“Visit www.essex.police.uk/digital101 to find out more about our website reporting services.
“Alternatively, you can call us on 101. In an emergency always call 999.
“If you would like to make an anonymous report you can contact independent charity Crimestoppers, by visiting their website or by calling 0800 555 111.”
