The levolution in this map is one of the easiest to set off and one of the most impressive to watch happen. At the far end of the map there is a large satellite dish with a receiver hanging above it by wires. To the east of the map, there will be a concrete block with large cables coming out of it, and another concrete block on the far side. When both are destroyed, the cables will cease to hold the receiver above the dish.
It will come crashing down, causing the flag under the dish to be more obstructed, changing the flow of the map. It will take more than a few C4 charges or rockets to destroy the cables from the blocks, but once it goes, it is a pretty spectacular sight to behold.
On the main street that runs from one end of the map to the other, there are two open hatches in the street at each end. Inside each of the hatches will be a pipe that you can turn on to build up pressure within it. There will be labels with A and B and a light on each to let you know if the other pipe has been turned on.
Once both pipes have been activated, the pipe will blow and along with multiple explosions in the street, the large bridge that spans the main street will also collapse, causing the flag on it to change locations. Like the Smoke Stack levolution, this can be turned on and off, so when it will actually detonate and go off can be an uncertainty.
Siege of Shanghai
This levolution is the most well-known of the bunch and is the collapse of the large skyscraper in the center of the map. To make the beast of a building coming crashing down, simply go to the front of the building and you will see 4 pillars at the entrance.
Destroy these 4 pillars with any explosives you have—although preferable to be in a tank—as it can take a bit of time, but once each pillar has been destroyed enough, the entire building will come crashing down and bring along with it the flag point that was on top of it. Now to get to the capture point you don’t need to go all the way to the top and it can be a much more furious battle with it on ground level.