This is the time to gain storage.
Go to the enemy gang's area and clip 3 guards. Then fire from far to these of opponents , who are going downstairs. After that go upstairs on the 3 of height and go down. After a while 4 enemies will appear - kill them and go upstairs. Four opponents will be waiting for you. Be careful, on the roof are fuel tanks.
After that the storage will open. There are other enemies. Go quickly to the edge of building and kill how many as you can. Run down, stand in half of stairs and wait. When the opponents come, kill them. In this way you have gained the storage!
After the fight, Sandman will call, he wants to incorporate you, so go to the islands!