"Six or seven times," he said.

Next, he said he heard a window break. Someone called the police. Before Du escaped from the window, he saw a man with a mask.

Du, a human capital and society senior, walked across Grand River Avenue with an injured foot from the fall, trying to warn people around him. Luckily, his classroom was on the first floor so he didn't suffer a severe injury. 

When he found safety off-campus, he started texting his friends. He was also able to reach his family in China despite the time difference.

"I hope everything will be okay," Du said. "And everyone is kept safe."

Du escaped Michigan State University's mass shooting. The shooting left three dead and at least five injured.