Later, the suspect, identified as 17-year-old Robert Butler, Jr., was found dead in car about a mile away from the school after shooting himself, Omaha police chief Alex Hayes said.
It was not immediately clear why Butler, a son of an Omaha police detective, shot Millard High School Principal Curtis Case and Vice Principal Vicki Kasper.
Case was in stable condition and Kasper was in critical condition at an area hospital, the chief told reporters.
A 16-year-old student at the school told The Associated Press she was just beginning lunch when a school administrator came into the cafeteria.
"He was like yelling, 'Get in the kitchen! Get in the kitchen!' He was waving his arms. You knew something was wrong and it wasn't a drill," said Laura Olson, who is the daughter of an AP reporter.
Olson, a junior at Millard, estimated that she'd been rushed into the kitchen with several dozen students around 12:45 p.m. Hayes said police first received reports of the shooting around 12:50pm.
The school was on lockdown after the shooting, but by 3pm, students were being released in groups from the school. Parents were allowed to pick them up at a nearby church.
The high school sits on the west side of Omaha, within city limits, and has about 2,100 students.
"We need prayers and we need hugs," Omaha Mayor Jim Suttle said.
