It's funny, growing up on the South shore of Long Island, we had all kinds of storms. Including snow, blizzards, ice and hurricanes. But, I have no recollection of ever losing power.
Not sure when you left, but as I look around I see many trees that were probably fairly small, or at the very least, much younger and healthier when the last big wind hit long island back in 1985. There are or were a lot...A LOT... of old trees that simply couldn't withstand the forces that hit them. This tree damage hit some areas far from the beaches and flooding very hard on north shore and in middle of island as well.
As for Sea Gate, I always felt that was a scary place just rip[e for this kind of destruction. There were houses right on the ocean with no dunes or natural barriers. We have become very bold and built things in places they probably shouldn't be. 50+ years ago many of the communities that were devastated were summer or weekend cottages, with small shacks, not permanent residences. When we build in dangerous places, like beaches or river flood plains these kinds of disasters are inevitable.