"Get to the Comm Tower to Find Bella and Reid" is a mission objective in the game Aliens: Colonial Marines
No Hope in Hadley's
Watch for Xenos
Note: You will arrive eventually at the Communications Tower Doors which will be locked, so you might think that you are stuck, but actually all you have to do is kill the Xenos in that area, and then O'Neal will open the door.
Also, past that door you will find a legendary weapon, Gorman's Pistol. See: