His wife, Marlina, and two sons, Arieh and Joe, have already begun making arrangements for his burial in Israel.
Prof Librescu at his grandson's brit, three years ago (Reproduction: Yaron Brener)
The Virginia Tech Police Department identified the campus gunman as Cho Seung-Hui, 23, a student and native of South Korea.
An official at the South Korean Foreign Ministry said that it could not rule out that the shooter was from South Korea but said it had not received any such notification from the US Embassy.
One of Prof Librescu's students, Alec Calhoun, who was with him at the classroom when the shooting started, told AP that at about 9:05 am, he and classmates heard "a thunderous sound from the classroom next door, what sounded like an enormous hammer."
When students realized the sounds were gunshots, Calhoun said, they started flipping over desks for hiding places. Others dashed to the windows of the second-floor classroom, kicking out the screens and jumping from the ledge of the room.
Calhoun said that just before he climbed out the window, he turned to look at the professor (Librescu), who had stayed behind to block the door.
Students mourn the loss of friends after Virginia Tech massacre (Photo: AP, Sam Dean)
Librescu's wife drove him to work on Monday, and he was killed about an hour later. His daughter-in-law Ayala, who is married to his son, Joe, told Ynet: "I heard he blocked the door of the classroom he was teaching… he must have realized that the murderer was approaching. He saved his students and was killed by gunshots."
"He has been teaching there for 20 years, and was a senior, world-renowned lecturer. He is the professor with the highest number of publications in the history of Virginia Tech. In the past, he taught at Tel Aviv University and the Technion," she added.
Ayala said that her father-in-law was passionate about his research and a dedicated family man.
A true gentleman
Prof Librescu and his wife are both Holocaust survivors who immigrated to Israel from Romania in 1978.
Librescu was an accomplished scientist in Romania, and the Communist regime had tried to prevent him from making aliyah to Israel. He was allowed to leave the country only after the Israeli prime minister at the time Menachem Begin appealed the matter to President Nicolae Ceausescu.
Several years later, Librescu left for a sabbatical in the United States and has remained there since. His first son, Arieh, lives in Israel, while his other son, Joe, resides in the US.
"I understand from friends that my father was a hero," the son Joe told Ynet. "In fact, by blocking the door with his body he saved all the students who were in the classroom."
Joe said that his parents were very happy in the United States, where they have been living since 1984. "He and my mom led a simple life, at a pastoral place in West Virginia, between hills and mountains, and he loved the school in which he taught."
"He is scientist who did not work for money, but for the pleasure he got from his occupation," he added.
AP contributed to the report