Boston University said Lu, a student there, was watching the race with two friends when the bombs detonated near the finish line.
According to media reports in China, Lu was from the town of Shenyang, in Liaoning province. She studied at the Beijing Institute of Technology, majoring in international trade, after graduating in 2008 from Shenyang’s well-regarded Northeast Yucai School.
More than 19,000 people in China left messages or digital candles on Sina Weibo, the Chinese equivalent of Twitter, in Lu’s memory.
“Can’t God hear the prayer of so many people? Why make so many people heart-broken? I wish it were a dream,” wrote one university schoolmate, with the Weibo identification “Vera Yu Yuanyuan.”
“We would go to class together, and chat in the classroom after waking up.”
On her own Weibo account, Lu would post photos of her dog, Dudu, and some of her favorite foods, a search of the Web site showed. Her last post, from Monday, showed a picture of a fruit and bread salad, captioned, “My wonderful breakfast!”
The Chinese state news agency Xinhua said President Xi Jinping “expressed sorrow for the dead student” without identifying her, apparently because her family had requested at first that her name not be released.
Xi also expressed condolences to Zhou Danling, Lu’s friend and fellow graduate student, who was injured in the blast, Xinhua said.
Zhou is a graduate student majoring in actuarial science, according to Chinese media reports. She is from Chengdu in Sichuan province and studied economics and finance at the Economics and Management School of Wuhan University in Hubei province. Her mother is a history teacher.
Boston University, which did not identify Zhou by name, said she has been visited in the hospital by school officials and is in stable condition after undergoing surgery Monday and Tuesday at Boston Medical Center.
“She is doing well,” Robert Hill, dean of Marshall Chapel, was quoted as saying on the university’s Web site. “She has her friends around her, and she will soon have family around her.”
The third Boston University student was not harmed in the bombings.
Mufson reported from China.