Less than 24 hours before she died, Lu Lingzi sent an exuberant email to a professor after learning she had passed part of a major final exam.

"I am so happy to get this result!" she wrote. "Thank you very much."

Lu was killed Monday during the Boston Marathon explosions, according to a statement from Boston University. She was a graduate student studying mathematics and statistics and scheduled to receive her graduate degree in 2015.

Lu was at the finish line of the race with two friends from BU. One, Danling Zhou, had surgeries Monday and Tuesday and is in stable condition at Boston Medical Center, the university's statement said. The other was unharmed.

On Monday morning, Lu put the finishing touches on a group research project she was planning to present at a statistics conference.

She also posted a photo of the breakfast ― bread chunks and fruit ― she ate the morning she died.

"My wonderful breakfast," she wrote.

Lu was a vivacious chatterbox who had lots of friends on campus, said Tasso Kaper, chair of the mathematics and statistics department, whose face lit up talking about his former student.

"The word bubbly ― that's kind of a corny word ― but that describes her very well," Kaper said.

Lu loved the springtime and kept asking when the trees would bloom in Boston.

"She was very interested in the flowers," he said. "Spring is a very important time of year for her."

Lu, 23, often shared photos of her home-prepared meals online, including a blueberry-covered waffle. They were almost always served in a shallow, blue-patterned bowl.

In September she showed off her first two-dish meal, stir-fried broccoli and scrambled eggs with tomatoes, often cooked by Chinese students learning to live on their own abroad.

She was described as an exceptional student and bright young scientist at Boston University, where she had been enrolled for about a year. She was in the process of searching for a summer internship with her adviser.

Lingzi would have had just one course left to complete in order to graduate.

Lingzi attended the Beijing Institute of Technology, where she graduated last year once got a perfect score on a differential equations exam. Her LinkedIn profile said she was awarded "excellent student" at the school and that she held jobs or internships at the Beijing offices of Deloitte Touche Tohmatsu consultancy and at Dongxing Securities Co. during her undergraduate years. She also spent a semester at the University of California, Riverside.

Chinese state media said Lu was from the northeastern city of Shenyang.

Lingzi's closest friends in Boston did not learn that she had been killed until Tuesday evening, when they were informed by faculty members. Fellow graduate students are struggling to process her death.

"Many of them are still in shock and disbelief," Kaper said.

A memorial service will be held at the campus chapel Wednesday evening. There was a small, private gathering of friends and faculty at the math department early Wednesday to "begin the long grieving process," Kaper said.

Reports of her death drew comments and condolences from friends and strangers, both on Lu's Sina Weibo account ― with nearly 20,000 comments as of Wednesday ― and on their own. Her former neighbor in Shenyang, Zhang Xinbo, lamented how the news brought home the tragedy of what he considered a faraway event.

"I saw her grow up, and a few scenes from the past are flashing through my mind. Now, she's becoming a girl, a bit Westernized, but a loud bang has changed everything," he wrote in a blog. "I think of her loved ones, and I don't know how they are coping with this painful news, while still searching for any thread of hope."

Many comments reflect a growing awareness that the burgeoning number of Chinese students and elsewhere in recent years has opened them up to dangers ranging from mundane street crime to terrorist attacks.

"Nearly 12 years after Sept. 11, more and more people have realized terrorists are the global enemy. They not only attack Americans but also Chinese, regardless of nationality or race," the well-known blogger and author Li Chengpeng wrote.