I helped muck out the store after the 1986 flood, also salvaging at the time the merchandise from the MythAdventures Fan Club, which I co-founded. The store let us operate the club out of the store during part of the club's operations.
The co-owner and manager of the store, Edward Luena, is the person who encouraged me to go to the 1984 Worldcon in Anaheim, an early step on my fannish life.
While it's sad to see it go, I have to agree with others that it is not much of a loss. None of the anchor stores came back after the 1986 flood. JC Penney, which had lost money from the start of the flood, concluded that it was cheaper to pay off the remaining years of the lease rather than try to come back. A few stores (including The Game Warden) made a go of it, but it didn't really work out.
Presumably the ruins will be leveled and flattened. Whether anything will ever work in that location is unclear.