Michigan State University students are describing the tense scenes on campus Monday night as the mass shooting unfolded, with one saying he encountered a woman with "a ton of blood on her." 

Ryan Kunkel, 22, was attending a class in the Engineering Building when he became aware of the shooting from a university email. Kunkel and about 13 other students turned off the lights and acted like there "was a shooter right outside the door," he said. 

"Nothing came out of anyone’s mouth" for over four hours, he told The Associated Press. 

"I wasn’t ready to accept that this is really going on next door," Kunkel said. "This is supposed to be a place where I’m coming, learning and bettering myself. And instead, students are getting hurt." 

MICHIGAN STATE UNIVERSITY STUDENTS HID IN LAUNDRY AND ON CAMPUS AS SHOOTING UNFOLDED

Campus police say two people were killed at Berkey Hall and another was killed at the MSU Union, while five people were in critical condition at Sparrow Hospital. The shooter eventually killed himself, police announced early Tuesday. 

Ted Zimbo said he was walking to his residence hall when he encountered a woman with a "ton of blood on her." 

MSU SHOOTING SUSPECT IS 43-YEAR-OLD BLACK MALE WITH NO TIES TO SCHOOL 

"She told me, ‘Someone came in our classroom and started shooting,’" Zimbo told the AP. "Her hands were completely covered in blood. It was on her pants and her shoes. She said, ‘It’s my friend’s blood.’" 

Zimbo said the woman left to find a friend’s car while he returned to his SUV and threw a blanket over himself to hide for three hours. 

Aedan Kelley, a junior who lives a half-mile east of campus, said he locked his doors and covered his windows "just in case." Sirens were constant, and a helicopter hovered overhead. 

"It’s all very frightening," Kelley said. "And then I have all these people texting me wondering if I’m OK, which is overwhelming." 

The Associated Press contributed to this report.