Suspect kills self after deadly classroom attack

3 are dead at two separate, but related crime scenes, according to police They were killed by "a sharp-edged weapon," though authorities did not elaborate The suspect "appeared to be completely alone," Casper's police chief says "This is the worst day of my career," the Casper College president says

(CNN) -- A man fatally injured one person, then burst into a Wyoming college class Friday morning to kill another person and, ultimately, himself, police said.

According to Casper police, "there were no firearms involved in the crime(s), and the (victims') injuries were caused by a sharp-edged weapon." It was not immediately clear how the three people -- one of whom was a Casper College faculty member -- were killed.

"I've been a college administrator for about 40 years, (and) I can say without a doubt this is the worst day of my career," said college President Walter Nolte.

Police Chief Chris Walsh did not immediately identify the three dead but said one was a woman and two were men, including the suspect. All of them knew each other, he added.

Authorities got their first call shortly after 9 a.m. MT (11 a.m. ET) about "a traumatic injury on the campus of Casper College." About 33 law enforcement officers from various agencies arrived within minutes, according to Walsh.

Casper College subsequently went on lockdown, as did the Natrona County Schools, as authorities tried to ascertain what happened.

As they canvassed the Wold Physical Science Center building, officers found two dead bodies in a third-floor classroom, the police chief said.

Meanwhile, two minutes after that first call, police learned of another "traumatic injury" at a site off-campus. Police are working under the assumption that this death is related to the other two and that the man behind all the violence is dead.

"There is no one at large, and there's no threat of violence or anything like that," Walsh told reporters early Friday afternoon.

The police chief said the suspect was not a current Casper College student, although he didn't elaborate or explain how the three dead knew each other. Walsh did say "the suspect appeared to be completely alone."