GRAND RAPIDS, MI Video of a stabbing on a Rapid bus Monday shows the assault appeared to be unprovoked.The attack on a bus at Kalamazoo Avenue SE and Elliott Street is described by Grand Rapids police as a "serious assault." The victim, a man, was transported to Mercy Health Saint Mary's with injuries that are not life-threatening. Video released by The Rapid shows a man stand up from the back of the bus and stab a rider in the ear area as he walks off about 11:53 a.m. on May 11. Police arrested the 41-year-old suspect shortly after the incident.