Weihan "David" Wang
Courtesy Fremont Christian School
The mother of one of Elliot Rodger's roommates is speaking out about her grief after losing her only son.
"I don't understand why this happened to me," said a devastated Jinshuang "Jane" Liu as she tried to come to terms with the loss of her son, Weihan "David" Wang, who was apparently killed
by Santa Barbara college student Elliot Rodger
Wang, 22, had told his mother that he wanted to move out of the Isla Vista, California, apartment he was sharing with Rodger, also 22, and two other students who were found dead: George Chen, 19, and "James" Cheng Yuan Hong, 20, both of San Jose.
The trio were apparently fatally stabbed by Rodger before he went on a murderous rampage, shooting three students dead and injuring 13 others before taking his own life.
Liu told NBC
on Monday that her only child, who was studying computer engineering at the University of California at Santa Barbara, had already found another apartment and planned to move with his friends next semester.
Wang, of Fremont, California, had complained that Rodgers played loud music in the middle of the night and wasn't very social. "Normally, they don't talk to each other," Liu said of her son's interaction with Rodger.
Rodger, the son of a Hollywood director, wrote a 141-page manifesto about how he wanted revenge on the world, and said in those writings that he planned to kill his roommates.
Liu, a nurse, was at work on Friday when she received a call from police. "For two days, I was not able to sleep," she said. "I still don't know what to do with myself."
Her son, who was supposed to have come home for the summer on June 12, was "a very, very nice boy," said Liu, whose husband Charlie Wang, sobbed as he stood by her side. "He was always the joy of the family."
Wang, who graduated from Fremont Christian High School in 2012, "was a wonderful young man," Dr. Tricia Meyer, head of the school, tells PEOPLE. And a statement
on the school's website says, "He was a young man of exemplary character and high academic achievement who loved basketball and was beloved by faculty, staff, and students."
Liu told NBC that her son was very close to the other two UCSB students stabbed in the apartment.
Chen "was a shy little guy … full of smiles toward his friends and classmates," his friend Ashlee Chai tells PEOPLE. "He was a diligent worker in class, but sometimes he would space out, which would be funny."
Armin Samii, who was the teaching assistant in a class that Hong took as a high school student at the University of California at Berkeley, tells PEOPLE, "He was extremely bright. He outperformed 90 percent of his class of college undergraduates while he was still in high school (as the sole high school student in the class). He was always curious, always asking questions and always helping other students. I can only imagine what he would have achieved once he graduated."
"James was a nice guy," Hong's classmate Andrew Pagan tells PEOPLE. "I remember his laugh in class and his voice was unnormally deep for his figure. He had such a rich laugh. Anyone who heard it would remember it without a doubt."
Wang's parents told NBC that they were heading to Santa Barbara to be with the parents of the other slain students. "I wish I could go in exchange of my son's life," Liu said. "I'm just heartbroken. You just can't imagine for a mom."
Reporting by MELODY CHIU