For the past several months the Port Authority has led a concerted effort to enhance the security of the PATH tunnels that cross beneath the Hudson River. The four underwater railway tunnels connect New Jersey to lower and midtown Manhattan. They serve a substantial commuter population and were the target of a foiled terrorist plot in 2006.
Efforts underway include lowering blast-resistant “blankets” over the top of the tunnels to lessen the impact of detonation from within. Other measures include floodgates at the entry points and reinforcement of the tunnel structure itself. All of these measures are important for critical infrastructure security.