Final answer:
Verbal communication was used by the Coordinator of Fire Safety and Alarm Systems to make a shelter-wide announcement to all building occupants.
Step-by-step explanation:
The type of communication used in this scenario is verbal communication. Verbal communication involves using spoken words or vocal sounds to convey messages. In this case, the Coordinator of Fire Safety and Alarm Systems used the public address system to make a shelter-wide announcement, which required speaking to transmit the message to all building occupants.