It was a usual Monday for 21-year-old Colin Goddard and his classmate Kristina Heeger on the morning of April 16, 2007.
Goodard, who had picked up Heeger on their way to a 9am French class in room 211 at Virginia Polytechnic Institute and State University, had considered the notion of skipping class.
The fateful decision to attend that day would change his life forever.
"We were debating in the parking lot whether we skip and have breakfast or go," Goddard told ABC News this week, 10 years on.
"It was close to the end of the year and we figured, you know, we should go."
He arrived five minutes late to class that day, 25 minutes behind class mate Rachel Hill, who explained she was late due to a shooting in her dormitory that morning.
Her building had been in lockdown and she had finally been allowed out.
Less than 25 minutes later, Rachel would be one of the first to be shot dead, in her chair.
"She never made it to the floor," said Goddard.
Little did they know at the time, Seung-Hui Cho, a mentally-ill student, was heading directly their way.
By the end of this awful massacre, he would shoot 11 students in this classroom dead, as well as their Professor.
Only six would walk out alive.
"That was the first time we'd heard of it. There was no email, no alert, nothing," Heeger would retell later.
Cho would terrorise victims in three other classrooms, one a German class, spraying students with bullets several times.
Those bullets were designed with a hollow-point, which unfurls "like flower petals" when it hits flesh, creating "devastating internal wounds".
He would kill a total of 30 after the attack in Norris Hall and another two in a dorm room attack. All of this in just 11 minutes.
His rampage remains the second deadliest shooting in US history.
A massacre that claimed 49 lives at an Orlando, Florida, nightclub surpassed it last year.
As Cho made his way towards the class, the students began to hear a sound described only as "bangs".
The students didn't see any need for alarm - Virginia Tech had been undergoing construction and they thought the gun shots were noises from the work site.
But as they got louder, and closer, students began to get nervous.
"We all started looking at each other were like, 'what was that?'," Goddard said.
French teacher Professor Jocelyne Couture-Nowak peered outside the classroom door before slamming it shut.
"Get under the desks and call 911," Goddard recalled his professor alerting the students.
Cho was attempting to enter the class room.
"For the first time in my life, I called 911 from my phone and heard a woman's voice and tried to explain to her that I thought there was someone at our school shooting a gun," Goddard said.
"By the time I got out where we were and which building and which floor, we had bullets coming through the door," he revealed in 2010.
"The next 10 minutes was the longest 10 minutes of my life. It felt like hours. It was absolutely terrifying. Like nothing you can imagine on television or anything you've seen before. It was totally terrifying."
"It was the most scared I've ever been in my life. I don't remember having the thought of, 'I'm going to die.' All I can remember thinking was, 'I just can't believe that this is real'.
Meanwhile, Matthew La Porte, a 20-year-old political science major, was attempting to stop Cho from breaking in.
"Matthew was trying to secure the door so the shooter couldn't come in," Matthew's mother, Barbara La Porte, said.
He was shot seven times.
"He fell with his arms out stretched towards the door."
Cho made his way through the barricaded doors. There was no time for the students.
He walked in, went to the opposite side of the classroom, and began shooting.
Throughout the course of the massacre, he would enter classroom 211 multiple times, pointing his gun towards Goddard's row of desks.
He was shot four times. It smelt like fireworks.
Heeger was shot twice in the back and once in her toe.
"After that last shot to the right shoulder, you could hear the police on the scene," Goddard said.
"I threw the phone, trying to act natural with the bullet. The phone stayed open and landed next to Emily's head and she remained on the line with the dispatcher."
Emily Haas, meanwhile, was crouching for safety underneath her desk when Goddard took the fourth final shot to his shoulder.
Despite taking two near-bullets to the head and suffering grazes from the strikes, she picked up Goddard's mobile phone and stayed on the line with emergency services.
"When the shooting was over, the 911 operator told me the police couldn't get into my room, and asked if I could open the door," Haas told ABC News.
"After that, the police led me out of the building. I think one or two others were able to walk out of the room on their own, but the rest could not."
First responders on the campus began to catalogue each victim through a series of colour codes; yellow for serious, red for severe and black for non-viable.
"In a real disaster you take the people you can save first," David Stoeckle, who served as chief of surgery at Montgomery Regional at the time, told the Chicago Tribune.
"You've got to save as many as possible."
Classroom 211 was the last class to be attacked that day. It would be the same room where gunman Cho would end his own life, after firing 174 rounds.
Meanwhile, as the classroom massacre was unfolding, Bryan Cloud, an accounting professor at the same university, was in his office preparing for class when he heard of the shooting.
His daughter, Austin Cloyd, was in classroom 211.
Bryan and his wife, Renee, began frantically calling their daughter. She wasn't answering.
Panicked, they headed to a nearby hotel where surviving students were being reunited with loved ones.
But Austin wasn't there.
"We sort of hoped, 'That's where we'll find Austin,'" Bryan told ABC.
"Somewhere in that foggy aftermath, we sort of began to lose hope."
The next day, the worst was confirmed. Austin had been shot - and she didn't survive.
"Your future kind of goes away when your kids go away," he said.
"One of the good things that Renee and I decided pretty early on was that we were going to focus on trying to help the students at Tech heal by engaging them in the same sorts of service activities that Austin found meaningful."
Both Goddard and Haas would eventually graduate from Virginia Tech.
"Everyone thought I would transfer," Goddard said.
"I started at Virginia Tech and I had to finish it there. I think it was also a sense of not wanting him [the shooter] to knock me off my path. The school was incredibly helpful afterwards and that's where my friends were. My whole life was there."
Virginia Tech held a series of events to mark the anniversary of the deadly campus shooting on April 16, 2007.
Virginia Gov. Terry McAuliffe and US Senator Tim Kaine were among the 10,000 to 20,000 people on the Blacksburg campus for the solemn occasion.
Kaine, who was governor at the time of the shooting, said he still vividly remembers the horrors of that day, but has also grown close to many of the survivors and the victims' families.
"We're going with a lot of different emotions, but we wouldn't be anywhere else," said Kaine
In a speech Sunday afternoon, Kaine said April 16, 2007 remains "the worst day of my life."
Kaine had been governor for a year and a half when the shooting occurred, and said since that day he's kept in touch with many families who lost children, spouses or loved ones in the mass shooting.
Kaine recalled speaking with families as he was leaving the governor's mansion in 2010.
"I remember saying to them, I'll never understand what you lost, because I never lost a child, a spouse, a parent or a sibling," he said.
"But as somebody who has grown to know the biographies and stories of each of these 32, I begin to have a sense of what the Commonwealth lost, what the country lost, what the world lost on April 16, 2007."
- Additional reporting by AAP