Firefighters in NYC carry a PASS (personal alert safety systems) alarm that beeps if the sensors do not detect movement for 30 seconds. In a lot of the 9/11 footage, the beeps in the aftermath of the collapse were PASS alarms.
September 11, 2021
Firefighters in NYC carry a PASS (personal alert safety systems) alarm that beeps if the sensors do not detect movement for 30 seconds. In a lot of the 9/11 footage, the beeps in the aftermath of the collapse were PASS alarms.