According to the AAMVA manual, what should a school bus driver do with a radio microphone or cell phone before evacuating, if it is still operable?

AAMVA CDL Manual, Section 10.3.2 (Evacuation Procedures), p. 10-7

Staying in contact with dispatch or emergency responders after an evacuation can speed up help arriving. A driver who doesn't know this detail might needlessly re-enter a bus that's on fire or near a rail crossing just to reach the radio.