You raise an interesting point. From current accounts the condo was failing for at least 7 minutes prior to the collapse. I haven’t seen any reports that suggest the fire alarm went off before the total collapse.
I work in the industry. As soon as the water moves in the system the bells and lights start up, elevators fall to the ground floor. That should have set of alarms at the front desk, the alarm monitoring company and the fire department at the same time, unless someone silenced the alarm.