New York-based software developer and consulting company Redshift Technolo-gies is based just a few blocks from where the World Trade Center once stood.
Company president Juin Wang recounted his harrowing day to Computer Weekly. "I got news of the first crash at about 9am on Tuesday when talking to someone on the phone who mentioned their office was watching a fire in the World Trade Center," said Wang.
But, due to excessive Internet traffic, getting any details proved impossible until Wang managed to log on to a UK-based news site.
His attention then moved to checking the whereabouts of his own employees. "After getting the first call from the field that the subways were closed, I realised it was time to stop just watching the news and get the company organised. I decided to close the office and get help from the people already there to call everyone and tell them to stay at home," said Wang.
"Despite the telephone outages on land lines and the saturation of the cellular networks, we were able to track down almost all of our employees and immediate family, and take some small comfort in knowing that the rest should not have been in the area.
Despite suggestions that we should close the office completely and leave the area, we decided to stay to assist with communications - there was nowhere better to go for that. We spent the rest of the morning fielding calls from friends and family and relaying messages.
"From outside, we watched the streams of people walking north up Park Avenue. Many were covered in dust. It smelt like a demolition site. Everyone walked at roughly the same speed. For the first time in New York, no-one was passing, and no-one was in a rush. Few people talked, everyone was oddly calm. I realised they were in shock and most had no destination in mind. We tried to donate blood, but the hospital was out of bags."
Wang's efforts to act as a communication hub for employees and families was hampered by technical problems. The main link to the Internet began to fail, and there were difficulties throughout the night.
"My back-up ISP was also totally out of commission, with their primary and back-up trunk lines cut. Both continue to be out," he said.
"We were also cut off from our own co-located servers where we host our company e-mail, so to check messages I ended up using remote control on another server on a separate dedicated T-1 connection that was still up, and connected from there to our servers."