Verticle Lines and touchscreen not working (no drop)

Hi before I got on the subway this morning I put my phone in my pocket. Got on the subway and went to check my emails and the screen has verticle white and grey lines on it, and the touch sensor is no longer working. All other buttons work and it still gets notifications, vibrates, rings, etc. Any idea what caused this and if it is a free repair from apple? It had a cracked screen but the phone has been working fine with that for over 3 months so I do not believe it is related