Students and employees at Virginia Tech university have expressed their shock after a gunman killed more than 30 people in a campus shooting.
Witnesses spoke of fear and chaos at the campus
Witnesses spoke of fear and chaos, while those sheltering in halls of residence and classrooms told of confusion and rumour.
Professor Dennis Hong told the BBC he was at work on campus when he heard shots.
"I was working in my office and then I heard three 'bang bang bang' sounds and I looked outside and I saw a bunch of police officers, guns drawn, hiding behind trees," he said.
Many of the students also heard the shots.
"I recognised the sound of gunfire but was mostly confused," said Andrew Gisch. "I looked around at the other students on the drill field, most of them confused like myself."
"It clicked in everyone's head immediately the sound we heard was a gunshot and everyone started running."
Nicholas Macko told the BBC that the gunman tried to get into his classroom in Norris Hall. He described hearing multiple shots.
"I would say easily 80 or 100 shots, hard to count, it just goes by with adrenaline going, but many many many shots."
Fear for friends
As events unfolded, television pictures showed police cars and fleets of ambulances lined up outside the campus.
For those locked down in rooms across campus, there was uncertainty.
Two students, Krishna and Allison, told the BBC that as they waited in the library, it was hard to work out what was fact and what was rumour.
"We were kept in the dark a lot about exactly what was going on," another student, Andrew Capers Thompson, said.
Many students spoke of their concern for friends who they had not been able to get in touch with.
"It's more of a shock to me because I'm an engineering major," said Daniel Smith.
"When that list (victims' names) comes out, I know I'm going to see some friends on there and it's scaring me inside right now."
Liz Hart told the BBC that the identities of some of the victims were beginning to emerge.
"Unfortunately, by word of mouth, even though it hasn't been official and by people that we've known who've been witnesses, we have found out who some of the people are," she said.
And most people voiced utter disbelief at what had occurred.
"We are in total shock, and it's still setting in," said another student, Timothy Owen. "The fact that 20 people have been shot on my campus is totally unthinkable and unbelievable."