The lack of a functioning radio communications system within London's subway limited the response to the July 7 bombings last year, a new report has concluded.
Emergency workers were forced to run back and forth between trains, platforms and the surface to communicate since no mobile radio communication systems were available in the subway, known as the London Underground or "the tube."
The four bombs, detonated on a bus and at three Underground locations, killed 56 people and injured more than 700.
Near one of the bombing sites, Russell Square station, a "leaky feeder" two-way antenna system used by train drivers to communicate with their line control managers was damaged in the explosion.
Mobile phones do not work in the subway tunnels. Work on the aging subway system is difficult due to the narrowness of the tunnels.
The authority responsible for the Underground, Transport for London, is investing