The principal of Wisconsin's Weston School died at a hospital Friday after being shot by a ninth grade student earlier in the day.

Principal John Klang was critically injured Friday morning when a 15-year old student armed with at least two weapons entered the building and shot him. He was taken by helicopter to UW Hospitals in Madison, spokeswoman Lisa Brunette said.

John Klang died at approximately 3:30pm after undergoing surgery, according to a statement. The hospital says a team of surgeons treated Klang for gunshot wounds to the head and chest.

An autopsy is reportedly scheduled for tomorrow.

Sauk County District Attorney Patricia Barrett says the 15-year who shot Klang expressed to a friend several days ago that he was unhappy with homecoming and the principal at Weston High School. Barrett says she plans to charge the boy with first-degree intentional homicide.

The principal was apparently shot three times, according to Sauk County sheriff's Capt. Michael Haifemann. A janitor later disarmed the 15-year-old shooter, who was taken into custody by the sheriff's department.

The suspect came into the school and began firing one of his weapons, and was overheard saying, 'I'm not f---ing around with anyone,' Weston School District Secretary Jean earlier told local NBC affiliate WMTV.

Klang has been with the school for two years, and is believed to be 49 years old and married with children, Jean said.

A Richland County sheriff's official said students at the Weston School complex in Sauk County are safe. Police Chief Deputy Tom Hougan said the scene is secure.

"The students are safe," Hougan said. "The scene is secure."

Melissa Nigh, the school's dean of students, said middle and elementary students were sent home, although some students remain at the school as part of the sheriff department's investigation.

The small, rural school has no metal detectors, she said.

"I don't think there was any way of predicting this," Nigh said. "I really don't."

All activities are cancelled or postponed for the near future, according to administrators.

Sophomore Shelly Rupp said she heard five shots and ran out of the school. She said she turned around and saw Klang as he was shot.

"He was laying on the ground in the hallway," she said. "He had just a pile of blood by his leg.

The 16-year-old described the shooter as a freshman with few friends. She said he came to school with a 22-pistol and a rifle, but a janitor wrestled the rifle away from him.

"He was a little weird. He always used to kid around about bringing things to school and hurting kids," Rupp said.

After the shooting, she went to a nearby gas station, where other students and townspeople had gathered. Rupp described Klang as a good principal and who listened to students.

"He never raised his voice or anything to any of the students," Rupp said.

Resident Laurie Rhea, 42, said Klang had spent last weekend at the gas station washing cars for a homecoming fundraiser.

"It's horrible. All the kids just loved him," she said.

Cazenovia is a community of about 300 people about 60 miles northwest of Madison.

A gunman took six students hostage in a Colorado high school Wednesday and killed one before shooting himself. Click here to read the latest on that story.

The Associated Press contributed to this report.