FORTUNE -- As the Northeast recovers from Hurricane Sandy, power is back for much of New York City. But the southern tip of Manhattan, home to some of the country's most important companies, is still largely out of commission. Several major buildings, including the headquarters of three Fortune 500 companies - AIG, Guardian Life Insurance, and Verizon - were still uninhabitable on Wednesday. More of the city comes online each day, but flooding, power loss and cut-off steam lines have rendered many buildings uninhabitable for weeks or months. Scroll over the map for a look at who got hit.