Carl Sadler is 79 and lives near Lake George, in upstate New York. Nearly 20 years ago, Sadler worked in Manhattan — in the South Tower of the World Trade Center as an executive director at the investment bank Morgan Stanley. On 9/11, he was on the 76th floor when the first plane struck the neighboring North Tower, and he narrowly escaped before the second plane hit his building. Sadler later developed thyroid cancer and asthma, among a host of other long-term illnesses.