Marston, who played Michael McBain on "One Life to Live" from 2004 to 2007 after starring as Alonzo "Al" Holden on that show from 2001 to 2004, was involved in a single-car accident in Reno, Nevada, on October 30.
Police believe Marston was fatigued and fell asleep while driving. His pickup flipped several times. The actor was thrown from the vehicle through the windshield, and several vertebrae in his neck and back were crushed when he landed.
A statement released by his family said Marston underwent surgery November 4, and doctors were initially positive about the outcome.
"However, in the early morning hours of November 5 his heart stopped on two separate occasions requiring doctors to use an external pacemaker to regulate his heartbeat. He remains in critical condition, fighting pneumonia, a heart infection and irregular pulse."
On Wednesday, the family said in a statement that it was likely Marston would be a quadriplegic
as a result of the crash.
His mother, Elizabeth Jackson, had been sharing updates about her son on Facebook. Later Wednesday, she posted about her son's passing in a note that began "Dear family and friends, it is with a heavy heart that I share this devastating news."
"My beloved and cherished son, Nathaniel Marston, who was putting up the good fight until last night was not able to continue due to the traumatic and devastating nature of his injuries," the post continued. "Nathaniel passed away peacefully as I held him in my arms. Father William, myself and his second Mommy Lisa, and our dear friend Charlotte were by his bedside, he was not alone. His injuries, which Dr.'s did their best to heal were not responding to treatment and one after another his bodily functions failed to support his life."
Marston also appeared as Eddie Silva on "As the World Turns" and had small roles in several prime-time shows including "Blue Bloods" and "Law & Order: SVU" and films like "The Craft."