This 'infamous' call was on Sept 11th 1997, timestamp 1:08:17 in the following video:

This one might be challenging because caller (target 1) makes alarming claims:
• extra-dimensional beings are not what they claim to be
• have infiltrated a lot of US military and Area 51
• government knows about disasters yet to occur, and crucially,
• instead of moving populations to safe areas, they want major population centres wiped out so those few remaining will be easier to control

This caller was cut off by what seems to be an EMP attack (source - target 2) that took out the station transmitter or satellite, and local phonelines at the time.

'Brian' called back April 28, 1998 claiming it was a hoax and performed the same voice:

So several questions. Was it a hoax, psy-op, or limited hangout? Who/what caused the station outage and was it linked to the call? Any insight about the callers original claims?