An argument on a subway platform in midtown Manhattan turned deadly Saturday, leaving one man fatally shot and train service disrupted. Police were called to the 7th Avenue Station at 12:21 p.m., where they found an adult male with a gunshot wound to his chest. A spokesperson said the shooting occurred on the E train platform at 53rd St. Two or three men were possibly involved. Emergency crews transported the victim to Bellevue Hospital, where he was pronounced dead. No arrests were immediately reported. Trains that normally stop at that station were bypassing the area as a police investigation continues.