That's one faint gas leak.
Shanghai is a largest city in China.
Revenge of The Fallen film[]
Shanghai is evacuated after being suffered by a toxic spill. What the Chinese people doesn't know is this was just a made up because of the real danger: the Decepticons.
An advanced team of new Autobots is send to Shanghai to find the Decepticons, together with an elite, classified task force called NEST. After the NEST team lands and investigates the area, a nearby vehicle reveals his true form, being the giant Decepticon: Demolishor. After smacking down one of the allied helicopters, Demolishor and another Decepticon, Sideways race away, trying to escape from the Autobots and NEST team. With two Decepticons on the run, Sideswipe, The, twins and The Arcee Twins/Triplets are sent to after them. Sideswipe successfully killed Sideways (while Sideways is in vehicle form!). Optimus and Ironhide attack Demolishor and stop his escape. He says that 'The Fallen shall rise again' (Those were his last words). Later, at Diego Garcia, National Security Advisor Theodore Galloway says that the Autobots made a mess of Shanghai, but it was really Demolishor rolling into the road that caused the damage.
We don't wonder where Sideways is.
Revenge of the fallen game[]
Multiple missions are in Shanghai, in the Decepticon as the in the Autobot campaign.