9/11 Amateur Video: Newly Discovered Footage Shows A Confused, Frightened City (VIDEO)

Raw footage from Sept. 11 can be alternately terrifying, heartbreaking and fascinating. Although 11 years have passed since the attacks, the images and sounds of that day live on in the hours of footage captured by both amateurs and professionals.

In this 10-minute clip posted online earlier this year, New Yorker Chris Ryan records the day as he lived it-- traveling throughout the city on his bike.

As first responders stream toward the World Trade Center, Ryan and his brother Sean film the little bits of humanity that often go overlooked in tragedies of this magnitude: friends comforting those unsure of the safety of loved ones still inside the tower; neighbors calling out across rooftops for news about phone service; a teacher calmly evacuating students across a street crowded with confused onlookers; a homemade sign urging passersby to give blood.

Before the video comes to an end, Ryan turns the camera to his own face. "My mind says, this is not over," he remarks. "This is probably the beginning of something."

The Huffington Post attempted to verify the clip's authenticity, but the YouTube user who posted the clip had not responded as of publication time.

WARNING: Some parts of this clip may be disturbing for some readers.