HONOLULU -- Hilton Hotels Corp. is blaming shabby design and construction for a mold infestation that has forced it to all but gut a showcase tower at its Waikiki resort, and the company wants contractors to pay for the $55 million cleanup. In the nation's latest case of a building so mold infested that it has been deemed unusable, Hilton alleges that 18 companies and individuals who built the 453-room tower failed to protect it against mold infestation.