Giant tunnel plug could limit future subway flood damage

[...] officials viewed a tunnel plug under development by ILC Dover, a Department of Homeland Security vendor and supplier to NASA, to protect subway portals where grade level tracks transition to underground subways.

If successfully tested, the MTA hopes the technology could be applied to portals and stairwell locations throughout the system. The tunnel plug demonstrated inside the station is not designed for use inside the subway system, Cuomo's office said. — silive.com