Police are investigating after a woman was pushed down a flight of stairs at a light rail station in the CID on Wednesday morning, and believe the suspect may have stabbed a second victim a short time later. At 11:36 a.m., a Sound Transit security guard called 911 to report a woman had just been assaulted at the Chinatown-International District light rail station at 5th Avenue South and South Jackson Street. Police arrived and spoke with the victim, a 62-year-old woman who was being treated at the scene by Seattle Fire Department medics. The victim said she was walking up the concrete stairs o…