Daniel Lewin, co-founder and chief technology officer of Internet communication company Akamai Technologies, was on one of the two hijacked flights flown into the World Trade Center yesterday.

American Airlines confirmed that he was one of 81 passengers on flight AA11 from Boston to Los Angeles that crashed at 8.58am US time into Tower 1 of the twin-tower center. Nine flight crew and two pilots also perished in the suicide hijacking.

Lewin was 31, and leaves behind a wife and two children. His colleagues and friends were quick to offer their tributes.

George Conrades, chairman and CEO of Akamai, said: "Danny was a wonderful human being. He will be deeply missed by his many friends. Our thoughts and prayers are with Danny's family, friends, and colleagues during this time of national tragedy and personal loss."

Co-founder Lewin co-founded Akamai in August of 1998. The company provides content-delivery services for leading Web-technology companies. Geographically dispersed Akamai servers deliver advertisements, video, and other high-bandwidth content for the company's clients.

Lewin and a colleague developed algorithms, at the MIT (Massachusetts Institute of Technology) research labs, to solve the problem of Internet congestion. They developed mathematical algorithms for routing and replicating content over a large network of distributed servers.

"After doing that for a couple years, we realized we had built the underpinnings of a system that could be useful in the real world," Lewin told Infoworld's Chief Technology Officer magazine, which in March named him one of the nation's 25 most influential CTOs.

Before founding Akamai, Lewin worked at IBM's research laboratory in Haifa, Israel, as a full-time research fellow and project leader, while completing two undergraduate degrees at the Technion, Israel's premiere technology university. He received a bachelor's degree in Arts and Science from Technion, and a masters degree from MIT. Lewin was born in Denver, and raised in Jerusalem.

Apple holds significant interests in Akamai and uses its services.

An emergency number for Britons worried about friends and relatives in the US has been announced: 020 7008 0000.