The coke truck you're in gets pulled over by the cops. Grab the bags and prepare for a fight when they shoot the door out!
Once you've taken out the initial wave, start moving the bags into the warehouse behind the truck. If you have the bag throwing skill, you can throw them through this window to speed up the process.
Finish moving the bags into this small room at the end of the building and hold here. This room is close to two of the Loot zones, and serves as a great choke point.
After a while, the Loot van arrives in one of 3 spots on the map. If you're lucky he'll park through the window in the holding room, if you're unlucky he could be on the other side of the map.
Start moving the bags to the loot van, but don't throw them in until you have all the bags right in front of it. If you throw a bag in too early, you might get screwed, which I'll explain next.
As soon as you put a single bag into the Loot van, the escape van will start coming (and he comes fast). The bad part is, he's coming in hot into the line of fire, and if you don't get out fast, the cops will literally kill your escape. This is why you need to put all the loot bags in very quickly, so you can get down here and clear out cops for your escape.
The van drives in quickly and the cops start slaughtering him. If you cleared the cops out before hand, or were all standing on the evac spot when he arrived, you can get out safely with the van. However if they wreck your van, you need to wait even longer for a chopper to come get you out.