MERCED, Calif. — An assailant stabbed five people on a rural university campus in central California before police shot and killed him, authorities said Wednesday.Two of the victims attacked at the University of California, Merced, were taken by helicopter to hospitals for treatment, spokeswoman Lorena Anderson said. The three other victims were treated on campus.Student Alex Lopez was heading to his class when he realized something was wrong on campus."I was listening to a podcast, and there was a break in talking, and I just hear a gunshot," he said.He said police and first responders flooded the scene."You see this stuff all over the news and stuff and you see it happen to all these other schools," but you don't expect it to happen at your school, said Lopez, 21.The school remains on lockdown and classes have been canceled for the day.