A man was arrested after he allegedly stabbed someone over an argument about a subway seat—and then allegedly stabbed a second good Samaritan who tried to stop him from running away.

Police say the incident happened around 7:30 p.m. on Tuesday aboard a southbound A train in Manhattan when victim Steve Williams, 55, asked suspect Ronald Cundiff, 40, to move his bag from a seat so he could sit down. When Cundiff refused, they ended up in a struggle, and Cundiff allegedly stabbed Williams in the abdomen with a knife.

Cundiff then got off the train at the next station (police said it was Canal Street, though Williams said it was Fulton Street), and fled on foot with Williams chasing him. Police soon joined in the chase. A good Samaritan, 21-year-old Nicholas Cai, saw this happening and attempted to stop Cundiff. Cundiff then allegedly stabbed Cai before finally being stopped and tasered by cops in front of 70 Bowery.

While recovering in the hospital, Williams told the News that he has diabetes and recently had surgery on his foot, so he wanted to find a seat on the train. Cundiff was taking up three seats—one for himself, one for his backpack, and one for a grocery bag.

"Two or three people had come onto the train and asked him for a seat but he refused. I asked him but he didn't answer. So I said I would hold his bag until I got off at my stop," Williams, who was on his way to a job in Jersey City, said. "I lifted his bag, and he grabbed me around the throat. I grabbed him back by his shirt. Then he pulled his knife and stabbed at me four times. He hit me once in the side. I backed away and someone said, 'You're bleeding.'"

Cai told ABC he was trying to hold Cundiff when he was stabbed in the left shoulder. "They ran down the other side of the sidewalk and then they looped around crossing the street. And that's when I turned around and the guy was charging at me. I just figured I'd try and stop him," he said. He ended up getting three stitches for his injury: "Well I don't know if it was worth getting cut."

Police say that Cundiff has been charged with two counts of assault, reckless endangerment, criminal possession of a weapon, and resisting arrest.