During the Battle of San Francisco, Romeo 4 was assigned to secure the Bay Bridge, where they faced heavy KPA resistance. Romeo 4-4 can be heard later in the battle, reporting that their Lieutenant had been killed and that they had multiple wounded. After a short break in transmission, he can also be heard requesting immediate CASEVAC and stating that the squad is no longer capable of holding the bridge. This would mean that the United States Armed Forces had secured and were attacking from Oakland as well. The two airports there may have been the bases for the F-22 Raptors.
It is likely that Romeo 4 was a platoon, specifically the fourth platoon of an unknown company. This is supported by the fact the unknown man identifies himself as "Romeo 4-4" signifies that there were at least four squads under Romeo 4 and that their Lieutenant-typically commanders of platoons-was killed by the Koreans.