Stamatios Tzemis and his eldest daughter, Sophia, were working at the World Financial Center, across the street from the World Trade Center, on September 11, 2001. When they evacuated from their building they went toward the Hudson River and waited there watching the event unfold. They sheltered in the area during the collapse of both towers and did not evacuate from lower Manhattan until the late afternoon. Their delay in the leaving the area was in hopes of finding Jennifer Lynn Tzemis
, the younger daughter of Stamatios and sister of Sophia. Jennifer was at work on the 93rd floor of the North Tower when the attacks unfolded. She did not survive.