Your starting point is on a bridge crossing the (now dried) canal. You're somewhat in a hurry - not only because military helicopters may attack you, but mainly because there'll be a blowout in approximately 10 minutes. When 6 minutes are remaining, you'll be given a warning and a timer appears. Furthermore the area has alot of soldiers and snipers about so expect a fair amount of fighting... in other words, there are plenty of good reasons why you should make your way to the Sarcophagus as fast as possible.
Up ahead are two snipers - you'll spot the first on the right side and soon after (beyond the APC) a second one on the left.
When you head forward you'll start hearing transmissions from the helicopters and from this point on they may attack you. I suggest that you take the route to the east, following the road - careful though because it has some strong Whirligig anomalies near and a pocket of radiation. You can try to go west if you'd like, but all the times I've tried it I've run into alot of trouble, mainly because you'll come under almost constant attack from the helicopters.
Following the road east and north you'll soon come upon a dead soldier with an RPG - if you've moved fast you may actually witness him being obliterated by a helicopter. For some fun I guess you can pick up the RPG and have a go at the choppers, just for old times sake or somesuch. Up ahead you should be able to see two train cars. Move past them and follow the buildings towards the west.
Depending on how fast you've been moving there may be soldiers and snipers up ahead. If you sprint more or less all the way from the beginning of the level you can avoid them (this can be seen in the video) - but even if you have to go through them they shouldn't pose many problems. Further to the west you'll come to a gate - move through it and keep going west. I suggest that you move north and follow the wall since you'll be able to find cover... there are, among other things, a soldier with a RPG and a Gauss sniper further west, and you may also be attacked by choppers so staying close to the wall and the nearby structures providing cover seems like a reasonable idea. Further west you should eventually come upon a opening - inside you'll find the level transit to the Sarcophagus.
I know the description for this area may seem hasty - but there's actually not alot to it. Refer to the video for the precise route I usually take; the video is hurried (to keep it as short as possible) so I get shot alot, and I don't stop to loot bodies - actually it's because I'm a total newbie . But as you can see, there should be plenty of time for you to find good cover, search bodies, and the like... you know, watch the sky go purple and whatnot.