Yup. When Superman returned, Cyborg-Superman and Mongul blew up Coast City for reasons I can't properly remember.
As an impetus for Hal Jordan going cukoobananas, the destruction of Coast City wouldn't have been bad. Unfortunately DC kinda screwed the pooch on that front, 'cause:
a) Hal hadn't been spending ANY time in Coast City in, like, forever. The man had no roots there any more.
b) Weirdly, no one that Hal seemed to care about was left in Coast City when it went boom. None of his brothers, not Carol Ferris. The only person who was left may very well have been Kari Limbo (aside: comic book names are great).
c) In the two or three issues leading up to Emerald Twilight, Hal is seen kind of being well, not "ok" with Coast City's destruction, but definitely not a "cop on the edge" about it. Which makes sense, really... Hal Jordan's not really the kind of guy you expect to lose his shite.
So, when Emerald Twilight kicks off and Hal's all weepy about Coast City and wallowing in ring projections of his (way) former hometown, a lot of people were like "where'd THIS come from?" But still, clumsy writer transitions happen, so the new guy was given the benefit of the doubt.
But then Hal turned on a dime from "suddenly weepy about Coast City" to "and now I must destroy the Green Lantern Corps because the Guardians won't let me use my power ring to bring back the dead (or something)", and a lot of people just kind of threw their hands up and said "w the actual f?"
It's a good thing Kyle turned out to be a decent character (although his fridged girlfriend would've been better), 'cause the deck-clearing required for his intro was rough. And no, layers upon layers of retcons to "fix" the story don't make it any better.
It's still about a mile and a half more coherent and respectful of its readers than HiC, though. And coming from a charter member of H.E.A.T., that's saying something.