Two members of the YouTube group Schaffrillas Productions were killed in a car crash on the weekend.
Christopher Schaffer, 25, and Patrick Phyrillas, 22, tragically lost their lives after their vehicle crashed with a tractor-trailer in Upper Macungie Township, Pennsylvania, on Sunday, per CBS News.
The person driving the sedan, James Phyrillas - who is Patrick's brother - was wounded following the collision.
The trio were part of the Schaffrillas Productions YouTube group, which boasts almost 2 million subscribers.
When James, 25, was released from hospital, he revealed to his Twitter followers that he sustained fractured ribs, a punctured lung, and bruises all over his body.
"Home now after 3 days in the hospital, with my ribs fractured, my lung punctured, my body bruised, my heart broken," the grieving brother said.
He wrote: "Patrick and Chris were my best friends. Been trying to wrap my head around why I was spared. Where I go from here.
"I could say so many things about both of them. But the thought of doing so, especially in a public forum, makes me weep uncontrollably. Please allow me to mourn them both in private."
According to the Lehigh County Coroner's Office, Patrick and Schaffer died of blunt-force trauma head injuries. Their deaths had been ruled accidental.
The three men shot to online stardom back in 2015 with their YouTube Poop series.
Their videos included analyzing videos, live-action re-enactments of SpongeBob episodes, and "anything related to Tamatoa or Aardvark Matt Damon."
Schaffer's fiancée, Amber Amin, paid tribute to her late partner, who she described as "a wonderful son, brother, friend, partner, and so much more."
"His humor and kindness have touched the hearts of many," she wrote on a GoFundMe page.
Amber continued: "He was a wonderful son, brother, friend, partner, and so much more. My name is Amber, I am Chris's fiancee and I am fundraising for the Schaffer family for funeral arrangements and other expenses regarding Chris.
"All money will be going directly to his family. I want money to be the last thing they worry about.
"We appreciate the outpouring of support from everyone during these difficult times. I will provide updates on this page when I can."
James has confirmed that he will return to video-making when he is fully recovered.
He said Patrick and Schaffer will be making one last appearance in the upcoming Clone Wars Season 3 Retrospective.
"They have both recorded for the upcoming Clone Wars Season 3 Retrospective," James added.
"Chris has more of a cameo, but they will both appear again on the channel one last time. We also all filmed a scene together years ago for the yet-unreleased Shrek 2 Retold.
