Bomb could flood New York subway within hours:
The analysis, based on work by the Lawrence Livermore National Laboratory and leaked to the New York Times, suggested that the network of tunnels was more vulnerable than had been thought. A bomb that could be carried easily on to a train could make a 50 sq ft (about 4.6 sq metre) hole in the side of the tunnels and potentially breach both sides, the analysis found. More than 1m gallons of water would enter the tunnel every minute, putting at risk the lives of up to 900 passengers – the capacity of a crowded train. About 230,000 people travel every day through four train tunnels that lie along the bed of the Hudson river. The concerns over the fragility of these tunnels are thought to apply equally to several rail tunnels that connect Manhattan to Brooklyn and Queens under the East River.