Eight fire engines and around 60 firefighters tackled a blaze at a car workshop on New Road in Rainham.
A single-storey car workshop and a further car workshop with a mezzanine floor were both destroyed by fire. Seven cars were also destroyed by the blaze. Sadly, two dogs died at the scene.
Firefighters removed 12 gas cylinders as a precaution and cooled two of them to an ambient temperature as some cylinders can explode when exposed to heat.
Station Commander Neil Guyett said: "The whole of a single storey car workshop was damaged by fire. Firefighters remained at the scene throughout the night damping down small pockets of fire."
The Brigade's 999 Control Officers took 13 calls to the blaze.
The Brigade was called at 1657 and the fire was under control by 1959. Fire crews from Wennington, Dagenham, Barking, Hornchurch and Ilford fire stations attended the scene.
The cause of the fire is under investigation by the Brigade and the Metropolitan Police Service.