Zombie Apocalypse/Are You a Military Man?

You are the commander of a squad called "Barsy" (you can choose your gender). Your team also includes:
Marcus - Helicopter pilot, mechanic, participates in assault missions.
Kate - A female assault trooper, but there's not much else to say about her.
David - Assault/Machine Gunner. He most often carries a machine gun, but for less challenging special missions, he uses an assault rifle.
Alice - The squad's medic/assault trooper. She is nearly fearless and often participates in assaults and special missions.

So, you're sitting by the helicopter after a special mission, waiting for gas for the next one, but an hour and a half has already passed since you started waiting. The base is completely silent; no one is around. Kate looked up from her machine gun and spoke.

Kate: Why has it become so quiet? And where is the gas? Maybe I should check?
David looked up from the Machine Gun and said
David: Maybe there was an evacuation?
Marcus continued to rummage through the box of parts, Izzy something. Alice was sorting through the first aid kit and said
Alice: Indeed, it has become somehow quiet... Should I go check, Commander?