Is it possible to sue Tri-met bus transit system for intentionally leaving me behind with my expensive personal belongings still

It was the second bus on the sunday after christmas. Snow was still on the ground and there were few riders. We stopped at the transit center and the driver turned the bus off. I asked how long we would be there. He said four or five minutes. I stepped off to smoke and got back on. Because nobody got on or off, we made it downtown again early. We stopped and I asked again, how long? He said three or four minutes. I again stepped off. I left my back pack ($70) on the bus. It contained my brand new digital camera a Nikon d-40 ($570) a pair of water proof pants ($99), MY SS card and several insignificant items. I was off the bus only a minute and he just drove off. I banged on the bus window and he looked back and kept driving. I ran three blocks through downtown trying to catch up and could