Logan Williams, 'The Flash' Actor, Dies at 16

"I was so impressed by not only Logan’s talent, but his professionalism on set. My thoughts and prayers will be with him and his family during what is I’m sure an unimaginably difficult time for them," co-star Grant Gustin shared on Instagram.

Logan Williams, who played a young Barry Allen on the CW's The Flash, died Thursday according to multiple reports. He was 16.

Williams’ agent, Michelle Gauvin, confirmed his death on Saturday to the Associated Press. No cause of death was revealed, but Gauvin said his sudden death comes as a "shock."

A rep for Williams could not immediately be reached for more information, but according to Canada's Tri-City News, his mother, Marlyse Williams, said Friday she is "absolutely devastated" over his death.

Grant Gustin, who plays an adult Allen on the CW series, also shared news of Williams' death Friday by posting a photo of the young actor with Jesse L. Martin during the filming of the series pilot in 2014.

"I was so impressed by not only Logan’s talent, but his professionalism on set. My thoughts and prayers will be with him and his family during what is I’m sure an unimaginably difficult time for them. Please keep Logan and his family in your thoughts and prayers during what has been a strange and trying time for us all. Sending love to everyone," Gustin wrote in the post.

The Canada native played a youthful Allen for eight episodes of the CW series. He last appeared in the second season's episode "The Man Who Saved Central City." His other credits include starring in Hallmark's When Calls the Heart as Miles Montgomery and Max Johnson on Supernatural.

John Wesley Shipp, who played Doctor Henry Allen on The Flash, shared on Twitter that he was "heartsick" to learn about Williams' death. "He was 100% committed to playing young Barry Allen, and we missed him once we moved past that part of the story. Love and compassion to Logan’s family and friends in your grief," he wrote.

Erin Krakow, who starred alongside Williams in When Calls the Heart, wrote on social media that she was also "heartbroken to learn of the passing of Logan Williams."

Mitchell Kummen, another When Calls the Heart co-star who played older brother Gabe to Williams' Miles, said he is "beyond sad" over the news. "We had so much on set.... Loved hanging out with you. In set. You were such a talent. Sending love to your mom," he added.

The SAG-AFTRA Foundation wrote on Twitter Friday, "We are heartbroken at the loss of young @sagaftra member & @TheCW #TheFlash actor Logan Williams. We send our love and condolences to his friends and family."

April 4, 5:00 p.m. Updated to include Williams' agent confirming his death to the Associated Press.