>But a fight on Thursday on a speeding A train in Brooklyn that started with those taunts did not end there. It continued to escalate before a rush-hour crowd,

>But a fight on Thursday on a speeding A train in Brooklyn that started with those taunts did not end there. It continued to escalate before a rush-hour crowd, from words to fists to a blade to, finally, a gun. The encounter came just over a week after New York’s governor took the extraordinary step of ordering the National Guard below ground to make the trains feel safer. The shooting undermined the city’s message that riding the subway is, statistically speaking, quite safe.