As soon as Nicolas Leslie's parents found out about the attack in Nice on Thursday, they tried to call him. The calls didn't go through.
Leslie, a 20-year-old UC Berkeley student, was one of dozens of California students celebrating Bastille Day in France when a rented refrigerated truck moving at 25 to 30 mph crashed into a crowd on Promenade des Anglais, near Nice's Palais de la Mediterranee. At least 84 people were killed and 202 people have been injured, 52 of them critically.
Through a UC Berkeley study abroad program, 85 students from Berkeley and some surrounding schools were in Nice, many celebrating on the Promenade. As of Friday evening, the university had accounted for 84 of those students: everyone except Leslie.
Leslie's mother, who is Italian, dispatched family and friends in the area to check hospitals and try to find her son in person, said a family friend who was with Leslie's mother at her Del Mar home on Friday, but asked only to be identified by her first name, Antonella, to protect her privacy and the family's privacy.
Three other UC Berkeley students were injured in the attacks: Vladyslav Kostiuk, 23, and Daryus Medora, 21, suffered broken legs, according to a UC Berkeley news release. Diane Huang, 20, suffered a broken foot.
Kostiuk and Huang were released from an area hospital and have returned to their dorms in Nice. Medora was still in the hospital as of 5 p.m. PDT on Friday.
UC Berkeley student body president William Morrow doesn't personally know Leslie or the injured students, but has many friends who are participating in the program, including his chief of staff, he said in a phone interview Friday.
"I found out about the attacks almost instantaneously," Morrow said. "One of my good friends posted on Facebook saying they were in hiding, and there was shooting."
Morrow immediately contacted his friends on Facebook and iMessage to make sure they were safe, and spent time Friday talking to administrators about offering extra counseling and other resources to students, he said.
University officials are working with local police, the U.S. consular office and his family to locate Leslie, the university said.
"We have 85 over there. We found 84," said university spokeswoman Claire Holmes. "We're devastated … we're hoping that Nick is coming home."
Four of the 85 students attending the program through UC Berkeley have decided to return home immediately, said university spokesman Robert Sanders. Three more will leave this weekend. The injured students have decided to stay in Nice, he said. The program, a 15-day Entrepreneurship and Innovation program in Europe that is part of the international European Innovation Academy, is scheduled to run through July 24.
Leslie has visited Nice with family before, speaks Italian and English, and is familiar with the city, Antonella said.
The family is "concerned and they are grieving for everybody that has had any loss there and sending their prayers to everybody. They are confident that Nicolas is well," Antonella said. "He's not in any of the list of the deceased so that's comforting to them. They think that he might be in shock or just trapped some place and need the help of the police to get out."
Leslie is an only child who is "adored by everyone who knows him," said Antonella, who has known the family for 15 years. "He's a wonderful, caring, young adult, extremely motivated."
Leslie's uncle, Fabeo Bottini, and Bottini's wife, went from hospital to hospital looking for his nephew, the Wall Street Journal reported. He was staying in student housing, but didn't return to the building after the attack.
"Yesterday he was in the zone of the accident. From yesterday, we don't know — he is missing," he told the newspaper.
His uncle said a friend saw Leslie running away from the promenade as the truck was passing.
"Maybe he is alive, but I don't know, maybe he is confused," he said.
The truck driver was gunned down by French authorities. He was identified as Mohamed Lahouaiej Bouhlel, born in Tunisia on Jan. 3, 1975.
While there are 85 students participating in the program through UC Berkeley, some of them are enrolled at other college campuses, including UC Merced, UC Davis, James Madison University and the local Peralta Community College District, Sanders said.
The program director, Ken Singer, has visited the three injured students in the hospital, Holmes said.
University officials have suspended the program temporarily to observe three days of mourning in France, and will continue it through its planned end date on July 24. The university offered to fly students home if they wanted to leave before it ended.
According to Leslie's Facebook page, he is from Milan, Italy, and went to Torrey Pines High School in San Diego. Holmes said the missing student is known for being active in the campus community and has an interest in economics. He is a junior majoring in the College of Natural Resources.
Morrow also posted on Facebook Friday, reminding students at home of on-campus resources available to them. The Nice attack is the latest tragedy to strike the Bay Area campus in less than a month. "A reminder to Berkeley students that the Tang Center has increased drop-in advising with their CARE advocates if you are having difficulty processing," he wrote.
The campus is "still reeling from the loss earlier this month" of Berkeley student Tarishi Jain, Morrow said. Jain was one of 20 hostages killed July 1 during a standoff at the Holey Artisan Bakery in Bangladesh. Authorities said armed extremists stormed into the bakery, saying they wanted to kill non-Muslims. In a battle with security forces, six attackers were killed.
"It's scary how small the world can be sometimes," Morrow said. "And how easy it can sometimes feel to be disconnected from this violence."
Friends of Leslie have taken to Facebook to express their grief and encourage others to look for him.
"Please help find my friend!! He was out with us last night before everything happened, and in the midst of all the chaos he was nowhere to be found," reads one post from someone named Erika Ho, who is part of the Facebook group of participants in the study abroad program. "We are all praying for the best but please help by sharing this post and spreading the hashtags!!"
Vice Provost Cathy Koshland and dean of students Joseph Defraine expressed condolences for the families, students and French community for the "tragic event" and "senseless violence."
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6:30 p.m.: This story was reworked and rewritten.
5:41 p.m.: This post was updated with information from William Morrow.
4:59 p.m.: This post was updated with information about the injured students.
4:47 p.m.: This post was updated with online comments from friends of the missing student.
3:32 p.m.: This post was updated with an additional detail about an injured student.
3 p.m.: This post was updated with additional details about the injured students.
2:22 p.m.: This post was updated with additional details about Leslie's family.
1:41 p.m.: This post was updated with additional details on the international program and the missing student.
1:10 p.m.: This post was updated with additional details on the missing student.