This episode is from the WNYC archives. It may contain language which is no longer politically or socially appropriate.
First, the Yellow Alert (not meant for broadcast) alerts all control rooms in the metropolitan area to stand by.
Next, the Red Alert is sounded. The sirens are played and the official drill is announced. Listeners are instructed to take shelter and leave their loud speakers on.
Finally, the All Clear is sounded.
Audio courtesy of the NYC Municipal Archives WNYC Collection
WNYC archives id: 71773
Municipal archives id: LT1850