California - James Jones is a tough guy - you have to be to put in 27 years as a guard at San Quentin State Prison. But he's never experienced anything quite like the Muni ride of his life the other day.

"It was pure mayhem," Jones said of the slugfest between two women on the 9-San Bruno bus, and the crowd of riders cheering them on.

It all began about 3:50 p.m. Thursday when Jones offered his seat to a young woman with a small child.

"The next thing I know, she leaves the child, makes a beeline to the back of the bus and starts whaling on this girl about 5-foot-3, who gave it just as good," Jones said.

He still has no idea why the first woman, who had about 6 inches' height advantage on her opponent, launched the attack. He didn't stop to ask - he just jumped in between the two of them, and that's when everything went crazy.

"There we were, rocking down the street, being thrown from side to side," Jones said. "Some people were trying to help break it up, but others were cheering it on. It was like being in the middle of a riot."