The 911 attacks carried out on September 11, 2001 were a series of terrorist attacks upon the United States of America. Four commercial passenger jet airliners were hijacked on that morning and two of the planes were crashed into the Twin Towers of the World Trade Center in New York City, one plane into each tower, causing the collapse of both towers within two hours. The third aircraft was crashed into the Pentagon. Passengers on the fourth hijacked aircraft attempted to retake control of their plane from the hijackers, which crashed into a field in rural Somerset County, Pennsylvania killing all on board but in the process saving many other lives. Approximately 3,000 people died in these attacks. including a number of fire fighters and rescue workers.

The first demonstration of remote computing took place when a teletype terminal at the American Mathematical Association Meeting in Dartmouth, New Hampshire was used to communicate over phone lines with an attendant at the keyboard for input to George Stibitz's Complex Number Calculator in New York. The machine had been operational since 1 Aug 1940. In 1940, George Stibitz's Complex Number Calculator was functional. He was a research mathematician at Bell Laboratories, who worked on its construction from Apr 1939, assisted by Samuel Williams. Later known as Bell Labs Model I Relay Computer, it used telephone relays and coded decimal numbers as groups of four binary digits (bits) each. It has been called the first electromechanical computer for routine use.