Footage has re-emerged of a high school class reacting to the news of 9/11.
On 11 September 2001, almost 3,000 people were killed after four commercial airliners were hijacked by 19 al-Qaeda terrorists.
Two of those crashed into the North and South towers of the World Trade Center in New York, while a third plane crashed into the Pentagon in Virginia.
The fourth crashed in a field in Shanksville, Pennsylvania, following a struggle between passengers and hijackers.
In a clip shared on Reddit and TikTok, a class of teenagers can be seen laughing and joking around for the camera.
However, just moments later, they are seen sat in complete silence as they look up at a TV screen in the corner of the room, with rolling news covering the devastating attacks that were unfolding.
One image shows a student with his hand to his head, before covering his eyes with his hand.
Another student can be heard in the background gasping: "Oh my God."
Some of the most poignant moments of our time have been captured on video, with people's ordinary lives interrupted by news that would change the world forever.
Earlier this year, a video resurfaced showing the moment a group of friends learned of the tragic death of Princess Diana in 1997.
Alan Light and his friends were playing some cards in Iowa City, Iowa, on 31 August when the sad news broke.
Alan was trying out a new camcorder at the time, and the footage he captured shows the room dramatically shift from a relaxed and playful atmosphere to one of shock and sadness.
Princess Diana died aged 36 following a car crash in Paris, in which her partner Dodi Fayed and driver Henri Paul also died.
Alan recently answered a few questions about the recording on his YouTube channel.
He said: "I was trying out a new camcorder by recording friends playing the card game UNO. When my mom called me to say that Diana was in a car crash I turned on the TV and I kept recording my friend's reactions."
He continued: "When CNN announced that Diana had died I didn't turn the camera back to the TV because I thought it was more interesting to capture my friends' reactions.
"Some people call this video the first of what are now called 'reaction' videos, a term that didn't exist in 1997 (and neither did YouTube)."Featured Image Credit: Reddit/TikTok