In El Segundo as teams gathered to play Wednesday evening, they mourned the loss of a man described as kind and gentle, and very proud of his affiliation with UCLA.
"It was shocking to say the least," said Lance Giroux, a friend of Klug.
"For a guy like Bill it's even more shocking, based on his personality and the kind of guy he was. To have something like this happen is just unfathomable."
Klug was a professor of mechanical and aerospace engineering at UCLA. He also received his master's degree from the school in 1999, then earned a Ph.D. from Caltech in 2003.
The UCLA website describes his research at the school as focusing on theoretical and computational biomechanics.
One of the early papers he coauthored in 2003 was a physics-based simulation of a bullet wound to the human skull.
Klug was married and had two children, a son in fourth grade and a younger daughter.
He earned his undergraduate degree in engineering physics in 1997 from Westmont College in Santa Barbara and remained connected with the school as an alumnus.
"We're deeply saddened by this tragic news and send our condolences to his wife, Mary Elise, also a Westmont graduate, and their family," Westmont College President Gayle D. Beebe said. "Professor Ken Kihlstrom remembers him as a gentle, kind person without a trace of arrogance. Dr. Klug was an excellent student at Westmont who conducted student research with two professors during his college years."
A profile on the Westmont website said his wife, Mary Elise Richter Klug, was also an engineering major at the school and does consulting as an aeronautical software engineer. They married in December 1999.
Klug's body was found in an engineering building on campus around 10 a.m. Wednesday, along with the body of another man who has not yet been identified.
Klug was identified as the victim of a homicide in which the shooter then apparently turned the gun on himself. A note was found nearby, but its contents have not been disclosed.
The discovery of the two bodies triggered a lockdown and massive search of the UCLA campus involving hundreds of officers from multiple agencies. Officials said at the time they were not sure if there was still an active shooter on campus.
By noon, police Chief Charlie Beck declared the incident was a murder-suicide and the lockdown was lifted.
Family and friends started a GoFundMe account to help support the family of Klug. If you'd like to learn how to donate, click here.
After the initial report came in around 10 a.m. of two men dead inside an engineering building, investigators weren't immediately certain if a shooter was on the loose on campus.
Hundreds of officers from multiple law enforcement agencies, including the FBI and ATF, flooded the campus in search of a possible gunman or gunmen and ordered students to remain sheltered in place.
Students who did move around on campus were told to walk with their hands up and were searched by officers. Classes were canceled and nearby middle and elementary schools were also placed on lockdown.
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The report of a shooting happened shortly before 10 a.m. at Boelter Hall.
By noon, LAPD Chief Charlie Beck said the shooting appeared to be a murder-suicide and a note was found, but would not elaborate if it was a suicide note.
"The campus is entirely contained," he said. "We believe there are no suspects outstanding and no continuing threat to UCLA's campus."
UCLA officials say classes will resume Thursday, while final exams and commencement will continue as scheduled.
"We want to resume normal operations as quickly as possible, so we will resume scheduled classes tomorrow morning," UCLA Executive Vice Chancellor and Provost Scott Waugh said. "Faculty, staff and students should show up tomorrow and go through their regular routines and complete the quarter as planned."
A large police presence remained at UCLA continuing to investigate after the lockdown was lifted and some areas of campus remained closed to students.
UCLA Police Chief James Herren said the campus police force is well-trained to deal with such incidents. The school immediately triggered BruinAlert, the campus alert notification system, to warn students and faculty of an incident that could be dangerous.
"We have a lot of resources here that we're dedicating to ensure the safety of the campus community," Herren said. "It is something that we have trained to do. So when our officers arrived on scene they immediately began putting teams together ... to help those who have been injured and also search teams to look for suspects who may (have been) in the area."
Mayor Eric Garcetti offered his sympathy to all affected by the incident.
"My thoughts and prayers go out to all those affected by what appears to have been a murder-suicide on the campus of UCLA," Garcetti said. "This horrific event, at an institution dedicated to learning and mutual understanding, reminds us once again of the fragility of a peaceful society."
President Barack Obama was also briefed about the incident while aboard Air Force One, according to a White House spokesman.