When American Airlines Flight 11 struck the North Tower , Praimnath started to evacuate from his 81st floor office in the South Tower , but he returned when the building 's security guards said the South Tower was secure , and workers should return to their offices . Soon after reentering his office , United Airlines Flight 175 crashed into the building . The left wing sliced through his office and became lodged in a door 20 feet from him . Praimnath was bruised and covered in debris after the crash , which left him stuck and unable to escape on his own . While Praimnath called for help , Euro Brokers executive Brian Clark , from the 84th floor , and a group of his coworkers were debating in the stairwell whether to descend through the impact zone using the stairwell , which they had been told was impassable , or to climb to the roof . Clark heard Praimnath 's cries for help , and made his way to him by using his flashlight and following his voice . As Clark was on his way to find Praimnath , he looked back towards his coworkers and saw they had decided to climb up the stairs instead of going down . Because of the decision to ascend the stairs , all of Clark 's coworkers were killed , except for one who reversed course
United Airlines Flight 175
United Airlines Flight 175
Stanley Praimnath