On July 26, 2009, Schuler left Hunter Lake Campground in upstate New York with five children and headed back to their home in Long Island. Her husband took the family dog in his pickup truck. The campground owner said nothing seemed amiss.
Schuler had borrowed the red minivan from her sister-in-law, Jackie Hance, and had promised to get her niece back for a ballet lesson.
Hance, 40, lost all three of her daughters in the crash, and yet she recently told Good Housekeeping magazine that Schuler was "the most responsible person I knew." She refused to participate in the documentary and is now pregnant after in vitro fertilization, due in September.
"People always ask how I feel about Diane," Hance told the magazine. "You can't imagine how complex that question is. How does a person go from being like a sister to me -- adored by my girls and cherished by my husband -- to being the one who ruined our lives?
Schuler stopped at a gas station looking for fast-acting pain medication -- perhaps for an untreated tooth abscess, the film speculates -- and might have tried to kill the pain with a bottle of vodka that the Schulers carried with them on vacation trips.
Witnesses said her van weaved in and out of lanes traveling down the New York State Thruway and the cries of children were heard in the car in a telephone call to her brother along the way.
Minutes before the deadly crash, Hance's 8-year-old daughter, Emma, had called her mother to say, "Something's wrong with Aunt Diane."
Schuler entered the wrong side of the Taconic Parkway, then drove at 70 mph for nearly two miles. Witnesses said her driving was not erratic but rather she drove deliberately down the fast lane with determined eyes.
Eventually, she slammed head-on into another vehicle, killing Guy Bastardi, 43, his father Michael Bastardi, 81, and a family friend, Daniel Longo, 72.
In the film, Bastardi's daughters say they have forgiven Diane Schuler, but not Daniel and Jay Schuler for denying her guilt in the crash.
Schuler's son, Bryan, who suffered a severe head injury that left him with ocular nerve palsy, has said he has no memory of the accident. He tells his aunt repeatedly, "Mommy's head hurt. She couldn't see" and, "I flew out of the car like superman."
It was Schuler herself who had appeared to have super-human powers. "She seemed to be good at whatever she attempted," her friend, Sue Troccoli, said. "She was very good at her job, and she was a take-charge person, too."