(SPARKS, Nev.) -- A middle school student shot and killed a staff member at Sparks Middle School in Nevada Monday morning and critically wounded two other students before he was killed, police said on Monday.
The school staffer likely died while trying to shield students.
"In my estimation he's a hero," Reno's Deputy Police Chief Tom Robinson said at a news conference.
The identity of the staffer and his position at the school were not released by police.
Police said they believe the second fatality is the young gunman, who was a student at the school.
Two male students were taken to Renown Regional Medical Center in critical condition, hospital spokeswoman Angela Rambo told ABC News.
Authorities said one of the students has been through surgery, while the second is said to be "doing well."
Washoe County School District Chief of Police Mike Mieras said gunfire erupted around 7:16 a.m., a "time in the morning students are arriving, buses are arriving, the walkers are coming in through the gates outside. Kids are congregating out back….waiting for their day to start."
Police are hoping to interview the estimated 20 to 30 witnesses who heard or saw gunfire as they waited for the morning bell to ring at 7:30 a.m.
Robinson said he hoped the interviews would help police determine the suspect's motive and whether he shot indiscriminately or was targeting specific victims.
"The best description is chaos," he said.
It was too soon to determine where the gunfire began, he said, however, police knew that the carnage ended outside of the school building.
Robinson declined to say whether the suspect died of a self-inflicted gunshot wound, but said law enforcement did not fire any shots.
The SWAT team and bomb sniffing dogs worked to clear the school Monday morning, however, police said it remains an active crime scene.
The 630 students enrolled at the school were evacuated to nearby Sparks High School, where they are waiting to be released to their parents, Washoe Schools spokeswoman Terry Bartek told ABC News.
Administrators said school has been cancelled for the remainder of the week and grief counselors have been brought in to help students and staff cope with the ordeal.
Gov. Brian Sandoval said he was "deeply saddened to learn of the horrific shooting" and is receiving regular updates from authorities who are working at the scene.
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