World Trade Center (1973–2001)
In the immediate aftermath of the attacks, media reports suggested that tens of thousands might have been killed in the attacks, as over 50,000 people could be inside the World Trade Center, although the National Institute of Standards and Technology (NIST) estimated that approximately 17,400 occupants were in the towers at the time of the attacks. Ultimately, 2,753 death certificates (excluding those for hijackers) were filed relating to the 9/11 attacks in New York City, including one filed for Felicia Dunn-Jones, who was added to the official death toll in ; Dunn-Jones died five months later from a lung condition linked to exposure to dust during the collapse of the World Trade Center. Three other victims were then added to the official death toll by the city medical examiner's office: Dr. Sneha Anne Philip, who was last seen the day before the attacks; Leon Heyward, a man who developed lymphoma and subsequently died in 2008 as a result of dust ingestion during the events following the attacks to the Twin Towers; and Jerry Borg, who died in December 2010 of pulmonary sarcoidosis determined in June 2011 to be the result of dust from the attacks. 2,192 civilians died in and around the World Trade Center, including 658 employees of Cantor Fitzgerald L.P. (an investment bank on the 101st–105th floors of One World Trade Center), 295 employees of Marsh & McLennan Companies (which was located immediately below Cantor Fitzgerald on floors 93–101, the location of Flight 11's impact), and 175 employees of Aon Corporation. In addition to the civilian deaths, 343 New York City Fire Department (FDNY) firefighters were killed in the attacks, as well as 71 law enforcement officers, including 37 members of the Port Authority Police Department (PAPD) and 23 members of the New York City Police Department (NYPD). Ten years after the attacks, remains of only 1,629 victims had been identified. Of all the people who were still in the towers when they collapsed, only 20 were pulled out alive.
Posttraumatic stress disorder
The September 11 attacks took the lives of nearly 3,000 people, leaving 6,000 injured. First responders (police and firefighters), emergency medical services, sanitation workers, and volunteers were all involved in the recovery efforts. The prevalence of probable PTSD in these highly exposed populations was estimated across multiple studies utilizing in-person, telephone, and online interviews and questionnaires. Overall prevalence of PTSD was highest immediately following the attacks and decreased over time. However, disparities were found among the different types of recovery workers. The rate of probable PTSD for first responders was lowest directly after the attacks and increased from ranges of 4.8-7.8% to 7.4-16.5% between the 5-6 year follow-up and a later assessment. When comparing traditional responders to non-traditional responders (volunteers), the probable PTSD prevalence 2.5 years after the initial visit was greater in volunteers with estimates of 11.7% and 17.2% respectively. Volunteer participation in tasks atypical to the defined occupational role was a significant risk factor for PTSD. Other risk factors included exposure intensity, earlier start date, duration of time spent on site, and constant, negative reminders of the trauma. Additional research has been performed to understand the social consequences of the September 11 attacks. Alcohol consumption was assessed in a cohort of World Trade Center workers using the cut-annoyed-guilty-eye (CAGE) questionnaire for alcohol abuse. Almost 50% of World Trade Center workers who self-identified as alcohol users reported drinking more during the rescue efforts. Nearly a quarter of these individuals reported drinking more following the recovery. If determined to have probable PTSD status, the risk of developing an alcohol problem was double compared to those without psychological morbidity. Social disability was also studied in this cohort as a social consequence of the September 11 attacks. Defined by the disruption of family, work, and social life, the risk of developing social disability increased 17-fold when categorized as having probable PTSD.