mass transit systems in cities across the country, they have increased patrols. pete, what s the response so far? we heard from the biggest public transit systems in the united states. they say they are monitoring the new york subway attack. that includes the washington, d.c. metro system, nbta, which operates the t in boston, bart in san francisco, septa in philadelphia and marta in atlanta. transportation secretary pete buttigieg was briefed. the department of transportation is offering support to the mta. the u.s. department of transportation federal transit administration also say they are monitoring this. here is what is changing now. mass transit systems say they are stepping up canine sweeps and police patrols. they underscore, they are face nothing credible threats at the moment. remember, service transportation is really hard to secure. securing sprawling transit