Cellular networks in Boston were still operating on Monday evening following the explosions near the finish line of the Boston Marathon, contrary to earlier reports that they had been shut down to prevent remote bomb detonations.
Mobile networks were straining under heavy voice and data use following the blasts, which occurred amid a massive annual event for which carriers had added network capacity. But despite reports quoting law enforcement as saying networks had been ordered shut down, services kept operating, according to sources and at least one mobile operator.
"Verizon Wireless has not been asked by any government agency to turn down its wireless service. Any reports to that effect are inaccurate," Verizon spokesman Tom Pica said in an email message late Monday.
The reports had said service had been shut off in the Boston area to prevent remote detonation of additional explosives after the two initial blasts. Cellphones have been used to set off bombs in the past, as in attacks on trains in Madrid in 2004.
But though cellphone service wasn't intentionally cut off in Boston, some callers had trouble getting calls through and carriers advised them to use text messaging or email instead, to leave voice lines free for emergency responders.
Verizon, AT&T and Sprint Nextel all reported capacity issues following the explosions, though all said their networks had not suffered any damage. Networks had been beefed up to deal with the crowds at the marathon, which was expected to attract about 27,000 runners, plus spectators, and takes place on a local holiday in Boston.
"We are experiencing some capacity issues at the moment," Sprint Nextel spokeswoman Crystal Davis said shortly after the blasts. Some callers had to try two or more times to get voice calls through, she said.
The capacity shortage happened despite Sprint having beefed up its cells near the marathon route, including at the finish line, for higher-than-expected traffic from the event crowds.
After the blasts, Verizon said it was enhancing voice capacity on its network in the Copley Square area, where the explosions took place. AT&T said that the extra Wi-Fi capacity it had temporarily turned on for the event would remain on "for an extended timeframe."