I'll almost bet the water mains running under parts of Lafayette/Michigan Ave area are older than 50 years...something similar happened when the Comerica Tower was built at Woodward and Larned/Congress/Bates when the water department tapped into 125 year old mains and caused a underground failure which caused the steam vaults to blow like a huge pressure cooker up and down Congress cutting off steam to all the downtown buildings in the area in the middle of a zero degree cold snap shutting down office for almost a week. Part of Congress Street collapsed and had to be filled in and repaired. The outside temp on Congress between Griswold and Shelby was 90f as the steam came billowing up through manholes and cracks in the street.