Like many, my memories of 9\/11 are personal and still vivid. At the time, I was Chief of the Technology Crime Unit of the Nassau County District Attorney\u2019s Office, the county immediately to the east of New York City. I always listened to local news or talk radio in my office, and on that morning I heard the announcement of a plane striking the World Trade Center.As most people, I interpreted it to be a stray two-passenger plane that bounced off one of the Towers. Still, I was curious enough to walk downstairs and enter the deputy chief investigator\u2019s office to watch his TV.Put four or five prosecutors and investigators in a room watching events like this unfold in real time, and the inevitable analysis of what we observed immediately began. The massive hole in the side of North Tower belied any possibility of this being a small plane. Moreover, the size and position of the impact point led us all to begin wondering if this was an intentional act.Moments later, all doubt was removed as we all watched live and in horror as the second plane made a direct hit into the South Tower.No one in that room needed to say another word or even watch the damage caused by the second plane. We all scrambled to reach out to loved ones, friends, and colleagues. The rest of the day was an unending frantic series of phone calls, text messages and emails to determine what had happened, what was still coming our way, what we could do to help, and whether our family, law enforcement comrades and friends were OK.No one was \u201cuntouched\u201d Despite living in a bedroom community immediately outside the city, no one I knew went completely unscathed from being affected by the loss of someone they knew either directly or once removed. I was very fortunate that I had no one that close to me on the scene that day, just friends and work acquaintances, and they all made it to safety. But similar stories began to unfold.The husband of my deputy bureau chief was a supervisor with the Port Authority Police Department and was one of the first responders. He stayed on the ground to coordinate rescue efforts between his staff and the other police and fire department agencies. None of his team, other than himself, survived the buildings\u2019 collapse. Moreover, her parents lived within close range of the WTC. She spent nearly the entire workday not knowing if any of her immediate family survived or, if they did, if they required medical care.My younger daughter\u2019s favorite elementary school teacher lost her husband who was an employee at Cantor Fitzgerald. She never returned to the school after 9\/11 and moved out west with her family as soon as she was able.On a more personal level, as a member of the NY Electronic Crimes Task Force and the NY chapter of the High Technology Crime Investigation Association, I routinely visited the Trade Center area at least once a month because both groups had their regular meetings at 7 WTC, the last of the three buildings to fall that day as the debris from the other Towers caused that building to suffer an uncontrollable fire.I later learned that my older daughter was hysterical at her middle school throughout most of that day because she was unsure if I had gone to downtown Manhattan.Because I was fortunate to work close to home, I was home watching on TV when 7 WTC finally collapsed at 5:21 pm. Just seeing that building succumb so many hours later, and the importance it had played in the relationships all of us in law enforcement had fought so hard to build in the cybercrime community within the New York City area since the mid-1990s, made the attack more personal and stinging.Little known lost evidenceWhat I didn\u2019t know until the following day was that the collapse of 7 WTC caused less visible irreparable damage. Stored within that building was evidence of various cybercrimes committed throughout the New York City area.Some local agencies that might not have the full forensic capabilities of the NYPD relied on federal agencies to do their analysis. Some of the original evidence from those cases was stored in evidence rooms located within 7 WTC.While I have no personal knowledge of how those evidence rooms were constructed, rest assured they were built to withstand virtually any form of traditional attack. One thing is certain, however, they could not withstand the incredible conflagration of that day.As difficult as it can be to revisit the events of 9\/11, every once in a while I will mention the destruction of 7 WTC when I need to convince IT personnel or C-Suite executives how unexpected and how devastating the loss of critical digital information can be. But I always mention it with an incredibly heavy heart.