I know that Safeco has handicap seating at the top of each aisle way on the first level, and I believe there is elevator or escalator access to that level. As for tickets I'd try the Mariners website, you should be able to get tickets fairly easily as the mariners have sucked for he better part of 10 years and the ticket rush for tickets is nothing like the Hawks, though the Yankees, Boston, and opening night will be the first ones to be sold out. Good luck.
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