Unsafe Haven is the 13th mission of Crysis 2. For this walkthrough, players will assist a group of marines in blowing up a building, in order to buy time and protection for the evacuation of New York City.

1. Follow the marines.
2. Lift open the gate on the right, and start moving towards the objective.
3. Ammo up at the objective point, and move towards the new one.
4. As the soldier will tell you, the army is trying to bring down the building ahead of you to block some of the alien fire. However, since the detonators did not go off, you will have to go there yourself.
5. Instead of jumping down, go around and over the bridge towards the objective
6. Clear out the aliens on the bridge.
7. Jump down where the bridge is broken, clear out the aliens just ahead, and go up the ramp towards the objective.
8. Continue clearing out aliens on your way to the objective, but keep in mind you don't need to kill everything. Just kill the aliens that are straight in your path to the building.
9. Activate the lock so that the parking garage doors will open. Go around and enter the garage.
10. When you enter the garage, the detonator locations will light up as the blue mission objective. Activate each one.
11. Get out of the building the same way you came in, and go to the new objective.
12. Note: a number of aliens will start appearing at this point, so either stealth/sprint past them or kill them quickly.
13. To get up into the new objective building, you will first have to jump up to the landing to the left of the objective location, and then up into the windows. Be ready for alien contact as soon as you get inside.
14. You won't be able to reach the objective on the second floor, as it is actually a floor up. To get to the third floor, jump into the open elevator shaft to the right of where you jumped up into the windows, and then jump up again towards the open elevator doors a floor up.
15. Move through the hallways towards the objective. 
16. You will automatically initiate a short cutscene when you reach the detonator remote.
17. Return back to the area where you were previously, with all the soldiers.
18. Clear out the bridge and move on.
19. The terminal is below the bridge you ran across earlier. Jump down, and head into the room to finish the mission.