Plaintiff Perini Building Co. sued defendants, including MGM Mirage, Infinity World Development Corp. and others, seeking to recover unpaid debt on the construction of the $8.5 billion CityCenter resort in Las Vegas. Perini is seeking $492 million in the suit, in which it claims MGM made numerous design changes and modifications that added millions of dollars to the project. Defendants claim Perini is liable for construction defects.