The morning of July 7 began normally enough for Alden Zecha, CFO and IT director with PrivatSea, a London-based company that offers yachting services. But as he arrived on foot at the Underground station near his home, he heard announcements directing commuters to evacuate the station and overheard talk about an explosion. His first reaction was skepticism: "You never know about those kinds of rumors," he says.What Zecha didn\u2019t yet know was that bombs had exploded in three subway trains and on a double-decker bus a few minutes earlier, killing more than 50 and injuring several hundred.On the street, Zecha turned to his BlackBerry to search for news on websites for the Underground system and the BBC, but these sites were not yet carrying up-to-date information about the attacks. Meanwhile, as Zecha made his way, by bus and by foot, to his office in southwest London, rumors were flying about bombs and terrorism.But thanks to wireless devices, detailed news about the bombings soon filtered to Zecha and others in the street. "Overall I think that this helped to keep people calmer," Zecha says. Zecha used his BlackBerry to e-mail the office, where colleagues were monitoring the news. He was also able to e-mail his family that he was unharmed. (Read Zecha\u2019s complete account.) People\u2019s reliance on wireless technology to communicate with loved ones was the reason London police decided not to shut down the city\u2019s mobile networks after the blasts, according to Metropolitan Police Commissioner Sir Ian Blair. Investigators of the Madrid train bombings last year have said that cell phones were used to trigger those bombs, but authorities in London decided the networks did not pose a threat.Like Zecha, many turned to text messaging and e-mail to share news of the disaster. The volume of e-mail traffic in Europe doubled in the hours after the blast, according to security company MessageLabs.Digital cameras and cell phones provided a way to share pictures and video as the events unfolded. Television news channels ran grainy video footage taken by a cell phone as injured passengers filed out of a tunnel near King\u2019s Cross Station. Mobile phone use reportedly surged again July 21, following four minor explosions across London\u2019s transit system.Zecha says that once he got to the office, his day passed normally, "other than the constant news updates." The office closed early, and Zecha and five colleagues who lived in the same direction walked home together. The streets were filled with people, also walking. It took Zecha one and a half hours to make his four-mile trip, past stores that had closed. "In one case we were told that a supermarket had to close early because their second shift couldn\u2019t get to the store," he says.