Then came the crash of 2000. Dozens of dot-com companies folded. By 2001, Akamai stock was selling for less than $5.
Leighton says Lewin never lost his concentration.
"We were both pretty focused on getting the job done, and that was true whether the stock was at 350 bucks or 50 cents," he says "It was positive reinforcement. If one of us got worried about a problem, the other would step in and say, here's how we're going to get past this one and here's why it's going to work out."
Nevertheless, things were particularly grim on September 10, 2001. Leighton remembers a session stretching late into the evening in which the executives had to decide whom to lay off, including some friends and colleagues who had been with them almost since the beginning. The next morning Lewin had to fly from Boston to Los Angeles.
"He probably barely got an hour of sleep before getting on board the next morning," Leighton remembers.
Lewin was sitting in seat 9B. With his Israeli military training and understanding of Arabic, he may have figured out what was going on, perhaps even tried to stop it. According to flight attendants' calls relayed to authorities on the ground, the first passenger to be killed was seated in 9B. He was stabbed to death.
Friends have always pondered the what-ifs. Lewin may have finished his Ph.D., something that always nagged at him. Friends thought he could have entered Israeli politics. Or he could have become a high-tech household name, like Bill Gates or Steve Jobs.
"Those who knew him feel like the world was robbed," says Raskin. "He was always searching for something greater."
Leighton, who helped keep Akamai going in the dark days after Lewin's death, wonders as well. Akamai has since become a multibillion-dollar company active in cybersecurity. Perhaps Lewin would have gone that direction, using both his mathematical mind and his military training to fight terrorism.
We'll never know.
"I think he could have done whatever he decided he wanted to do," says Leighton. "I think his potential was limitless."