The emergency services were called to Whalebone Lane South yesterday (April 30) around 7.15pm.
A video shows a white car on its side with another car crumpled into the side of a bus.
Firefighters freed the trapped woman and it is not yet known if there were any injuries or arrests.
Two fire engines and a fire rescue unit from Ilford and East Ham fire stations attended the scene.
A London Fire Brigade spokesperson said: “Firefighters were called to a road traffic collision on Whalebone Lane South in Dagenham yesterday.
“Four vehicles were involved in a collision, with one overturning onto its side.
“Firefighters released a woman who had become trapped inside a vehicle.
“The Brigade was called at 1918 and the incident was over for firefighters by 1939.
“Two fire engines and a fire rescue unit from Ilford and East Ham fire stations attended the scene.”
The Metropolitan Police and London Ambulance Service have been contacted for details.
