A man is in a critical condition and homes in Cranham have been evacuated following a suspected gas leak after a car is believed to have crashed on the A127 at the junction with Front Lane hitting a gas main.
Road closures are in place as emergency services deal with the after math.
The driver of the vehicle is being treated at the scene and is believed to be in a life threatening condition.
The air ambulance is currently on scene.
Motorists should avoid the area.
A tweet from Havering Police said:
Due to significant damage to the gas mains there are multiple road closures in place affecting the A127 /Front Lane and the M25 junction 29.