The Lore of the 2 ODST Teams

The ODST teams were sent to parts of a ring thats inhabited by the human race to contain the green flu, the origins of the green flu are unknown but the UNSC and scientists around the ring are theorizing that its a weaker mindless strain of the flood. Most ODST teams got overwhelmed by the infected or got infected by breathing without their helmets in the airspores of the infected.
thanks to the ODST helmets they are designed to battle all kinds of biohazards, they also get notified by their visor if their is any large biomass and the virgil AI will notify you if any special infected nearby. if your wandering why the warning sign is on the visor its because of the tank is its a large biomass.
The ODSTs were grouping up with other ODSTs in order to survive since the UNSC is calling all Remaining ODSTs and ODSTs teams to evacuate to a nearby helipad or a nearby pelican in order to retreat and plan the next action to contain the green flu before it spreads all over the ring since, so far the green flu taken over almost half the ring but spreading fast. the ODSTS you will see is coach, a leader of a ODST team that got overwhelmed by the infected and he was the only one left behind, Nick, a normal ODST solider is also in the same situation as coach but instead he is not a leader. Ellis and Rochelle are Advanced ODSTs but their team got overwhelmed by the infected so they are the only ones alive. all of these ODSTs bumped into each other while heading towards the last nearby pelican evacuating the remaning ODSTs and teams. then thats where the story starts for coach, nick, ellis and rochelle.

Now heres the lore of the other characters bill, francis, zoey and louis.
this is the only team alive in the city they are stuck in, Bill is the leader of the team.
They try to escape to the helicopters since all the pelicans are already gone so there are now helicopters sent in the city to search for remaining ODSTS.
soon as they escape onto the helicopter the person flying in the helicopter wasn't wearing their filter for their helmet which means the person flying the helicopter was already infected awhile ago then caused the helicopter to crash, just like what coach and nick and rochelle and ellis went through too. so they try escaping onto a island since all hope is lost since they can't contact the unsc due to communication array issues.
bill sacrfices himself to start the the bridge and that way the rest of the team members can escape to the island retiring from the ODST job and remain as MIA to the UNSC forever living in peace on the island thanks to bills heroic action.