I found it in the archives. Here it is:
> WASHlNGTON - East Coast and West Coast, the pattern has been the
> same: At about 11 a.m., an entire region's telephone system collapses.
> For the past six days, solving the mystery of the failing phones has
> become an obsession for the nation's service-conscious telephone
> companies. Yet despite recurring similarities and clues in the
> half-dozen failures to date, which have struck Washington, Los
> Angeles, Pittsburgh and San Francisco. the detective work remains
> mired in unanswered questions.
This was the subsequent problem on the AT&T network that affected only some 4ESS tandems in June 1991.
Here's an article you can read about all the "known" crashes in the early 1990s, including the one mentioned above:
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Dave Perrussel Webmaster - Telephone World
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