You will be left behind if the officer deems the apparatus sufficiently staffed to respond and you are still at your locker.
Firefighters train to don full gear typically in 90 seconds. This means boots, bunker pants, Nomex hood, and turnout coat zipped with collar secure in about 15 seconds in order to leave time to check and open your tank, check PASS alarm and gauge reading, check your surroundings, throw your pack on, secure your pack, don and pressure check your mask, raise your Nomex hood, secure your helmet, attach the regulator to your mask to go 'on-air,' and finally put your gloves on. This takes a lot of practice.
In actuality, we pack-up en route, often in the dark and sitting shoulder to shoulder after submitting name tags to the officer.