America Online, the world's leading on-line computer service, was finally switched back on yesterday after the biggest black-out in cyberspace left more than 6 million customers world-wide without access to their e-mail and favourite Web sites for almost 19 hours.
The on-line service crashed while new host software essential to operating the system was being installed on Wednesday morning. Normal service was only resumed in the early hours of Thursday.
The shutdown left customers ranging from newspapers such as the Chicago Tribune and the New York Times to small businesses and home-office workers staring at blank screens.
In Britain, subscribers missed hearing the seductive tones of actress Joanna Lumley greet them with "Hello" when they logged on and "Goodbye" when they logged off.
Members will be credited for a lost day of service, Steve Case, AOL chairman and chief operating officer, said.
Jonathan Bulkeley, managing director of America Online in the UK, was contrite: "Since I've been at AOL, this is the worst disaster I've seen," he said in an emotional e-mail to subscribers.
"I remember a flood we had a few years ago where the operations people had to run out and buy aqua-Hoovers to slurp up all the water in the computer room (six hours of downtime), the systems installation that went sour (eight hours downtime) and the transatlantic cables that were turned off for maintenance (seven hours downtime), but I can't remember a day like today."
He added: "I hope this will be the AOL disaster which becomes legendary - the day AOL went dark, the outage of `96, a distant memory."
Black-outs are becoming more common on the Internet and on-line services, reflecting the reliability problems that plague computer networks as they become more popular.
In recent months rival on-line services, including that of software giant Microsoft, have been disrupted by serious computer glitches.
The outage came at a sensitive time for AOL, hours before it reported fourth-quarter earnings. The company has already been hit by competition from the Internet, which has caused it to lower subscription fees. At the same time growth in subscriber numbers has slowed. Unhappy customers are the last things it needs.
With that in mind, a weary Mr Bulkeley signed off to his subscribers: "It's now 4:36 am on August 8th and I am going to sleep. Suffice it to say that we do not take this lightly. We do and will do everything possible to keep this from ever happening again."