At least 33 people, including the suspected gunman, were killed in a shooting rampage at Virginia Tech university.

WASHINGTON (Reuters) - Virginia Tech students described the mayhem on campus on Monday and criticized officials for not shutting the university down quickly enough after 33 people were killed including a gunman.

* Andrew Gisch, a second-year student, was walking across a quadrangle listening to his iPod when he heard "a big bang."

"I recognized the sound of gunfire but was mostly confused .... I looked around at the other students on the drillfield, most of them confused like myself....it clicked in everyone's head immediately the sound we heard was a gun shot and everyone started running. I went back to the dorm, locked the door, and turned on the news."

* Daniel Smith said he was aware of shootings at other schools but he never thought it could happen at this university

It hits you in the heart. It's more of a shock to me because I'm an engineering major and when that list (victims' names) comes out, I know I'm going to see some friends on there and its scaring me inside right now."

* Jason Piatt criticized the way university officials reacted after the first shooting.

"I'm pretty outraged that someone died in a shooting in a dorm at 7 o'clock in the morning and the first e-mail about it had no mention of locking down the campus, no mention of canceling classes," Piatt told CNN.

"They just mentioned that they were investigating a shooting," he said. "That's pretty ridiculous. Meanwhile, while they sent out that e-mail, 21 people got killed."