Quick thinking professor held office door shut at UCLA preventing the loss of more lives after his colleague was gunned down by a former student

UCLA professor Christopher Lynch (pictured) confirmed that he held William Klug's office door shut after he heard gunman and former PhD student, Mainak Sarkar, 38, shoot his gun twice

A quick thinking UCLA professor held an office door shut when a former student opened fire in his colleague's office in a murder-suicide Wednesday.

UCLA professor Christopher Lynch confirmed that he held William Klug's office door shut after he heard gunman and former PhD student, Mainak Sarkar, 38, shoot his gun twice, according to the Los Angeles Times.

'If he had stepped out, we'd all be in trouble,' Lynch told the newspaper.

Lynch said he didn't feel Sarkar try to open the door and he assumed the gunman killed himself when he heard a third shot.

'If he had come out with a loaded gun, I don't think I'd be alive,' engineering professor Ajit Mal told the newspaper. 

'Chris Lynch's presence of mind and quick action saved us.'

Both professors said Sarka had enrolled in their classes several years earlier but left little impression, according to the Times. 

Mal told the newspaper that Sarkar was quiet and reserved and would not greet him when the two men passed each other, which the professor found somewhat odd since both are from West Bengal in India and speak the same language.

He said: 'This whole thing is so incredible and bizarre because Bill is the least likely to have some conflict with students,' Mal said. 'He was so very caring.'

Lynch said he didn't feel Sarkar try to open the door and he assumed the gunman killed himself when he heard a third shot. Klug (left and right), who married his wife Mary in 1999 have two children together and met while they were both studying for their Masters at UCLA

Students held a candlelit vigil for the slain professor after he was shot dead in his office Wednesday morning by disgruntled former student Sarkar

Klug's wife, Mary, 40, paid a heartbreaking tribute to her husband by saying his death is an 'indescribable loss' adding that he was 'so much more than my soulmate'.

The associate engineering professor, who was known to loved ones as Bill, was shot dead inside his office at UCLA by Sarkar, who falsely accused him of stealing his work.

Mary, who had two children with her husband, said: 'During this extremely difficult time for our family, we are grateful for the tremendous outpouring of support.

Mary Klug, the wife of murdered UCLA professor William (pictured together), paid tribute to her husband, calling him 'more than my soulmate'

'This is an indescribable loss. Bill was so much more than my soulmate. I will miss him every day for the rest of my life. 

'Knowing that so many others share our family's sorrow has provided a measure of comfort. 

'That said, we are a very private family, and we need time to heal and recover from this senseless tragedy. 

'We ask the media to please respect our family's privacy in and around our home, school and local community during the days and weeks ahead, especially for the sake of my children.'

Mary, also an engineering graduate, met William while the pair were studying at UCLA together.

William, 39, once joked to Westmont University Magazine that 'I followed her there'. The couple married a short time later, in 1999.

He also credited his future wife with encouraging him to go into teaching, saying: 'I was a teaching assistant at Westmont and held help sessions for students. 

'Mary Elise often sat in on them and told me I should be a teacher. She kept talking about it.'

Police say before Sarkar shot Klug dead he also shot and killed his wife, Ashley Hasti, at her home in Minnesota and was intending to murder another UCLA professor, but was unable to find him. 

Officers investigating the shooting at UCLA say Sarkar had created a 'kill list' with those three names on it that was found at his home, also in Minnesota.

It is thought that he shot Hasti dead before driving to UCLA where he killed Klug with a 9mm semi-automatic pistol and then committed suicide.

Police said Hasti's body may have laid undiscovered for two days before officers found it. Investigators only knew to go to her house after finding Sarkar's list.

Klug spent his spare time coaching his son's little-league baseball team, friends said.

His areas of interest included computational structural and solid mechanics, computational biomechanics, and micro/nanomechanics of biological systems.

Pupils placed mementos next to the Bruins statue on campus and said prayers for Klug during a vigil held in his memory on Thursday night

Sarkar (right) is believed to have shot his wife Ashley Hasti (left) dead before driving to UCLA and murdering Klug. He is also thought to have been looking for another professor, but was unable to find him

He is said to have graduated from California Institute of Technology - Caltech in 2003.

Co-workers praised Klug as both brilliant and kind, a rare blend in the competitive world of academic research, according to the LA Times.

Alan Garfinkel, a professor and one-time collaborator with Klug, said: 'I am absolutely devastated. You cannot ask for a nicer, gentler, sweeter and more supportive guy than William Klug.'

California Lt Gov Gavin Newsom described him in a tweet as an 'empathetic, brilliant teacher'.

Melissa Gibbons, one of Klug's former PhD students, said he was an exceptional mentor and always tried to help out struggling students, once asking her to mentor an undergraduate who he felt needed extra instruction.

Chancellor Gene Block said: 'Our hearts are heavy as our campus family mourns the sudden and tragic deaths of two people on our campus.'

Around 200 armed police, SWAT officers, FBI agents and firefighters were called to UCLA to reports of three shots fired inside the Engineering IV building at around 10am on Wednesday.

Hasti's body was discovered in this house in Minnesota on Thursday after officers uncovered a 'kill list' drawn up by Sarkar with her name on it

Armed police swarmed UCLA's campus on Wednesday after reports of the shooting and students were placed into lockdown for two hours before being allowed back out

The campus was placed on lockdown for around two hours while officers went room-to-room searching for another shooter.

However, at around midday the campus was declared safe as police announced the shooting was a murder-suicide and no further suspects were being sought.

While the precise motivation for the killings is unclear, Sarkar had targeted Klug online in recent months, accusing him of stealing codes he wrote as part of his PhD.

LAPD detectives say the second professor on the kill list was involved in the same dispute.

However, investigators say the claims are false, adding that any slight by Klug was a figment of Sarkar's imagination.