There’s not much the MTA can do to prevent subway-pushing incidents like the two that ended in the deaths of Ki Suk Han and Sunando Sen this December besides encouraging passengers to be more aware of their surroundings. So, they’re increasing the frequency of the already-familiar order to, “Please stand away from the platform edge.” Most numbered lines (and the L) will hear the alert every time a train approaches and twice more every fifteen minutes, though many other lines will only hear it once every fifteen minutes. Sadly, the new system got off to an inauspicious start yesterday as a man was struck by a northbound train passing through the Church Street B/Q station.