(CNN) -- A bride is in mourning.
Hours after the wedding, groom William Riley Knight, 49, of Crown Point, Indiana, was struck and killed.
His new wife, Nikki Knight, was not injured.
"I went from a being a newlywed to a widow in less than 48 hours — the highest high to the lowest low," she told the Chicago Sun-Times on Sunday. "It's a blur."
They had just left their reception, according to Patti Van Til, a spokeswoman with the Lake County, Indiana, Sheriff's Department.
Nikki was still in her wedding dress, she said.
Knight was acting as a good Samaritan on Saturday night when he stopped to assist Linda Darlington, whose vehicle had slid into a ditch along a road in Crown Point. He climbed out to help while his wife waited in the car.
"He said, 'We've got to stop, it's late and they need help,' " Nikki, a registered nurse, told the Chicago newspaper.
"He was the type of person who was willing to put himself on the line and support you no matter what," she said.
Her husband and Darlington, 42, were struck multiple times as they stood by the side of the road. They were first hit by one vehicle, followed by two more. Darlington was also killed.
According to CNN affiliate WBBM, which spoke to Knight's ex-wife, he had four children, including two stepchildren.
He acted in community theater, was a hunter and reportedly served in the U.S. Army Rangers before retiring in the mid-1990s.
"He was very outgoing, always wanting to help somebody," said friend Rob Biella, CNN affiliate WLS reported. "He was good to be around my kids. I'm glad they got to know him."
All drivers remained on scene, and there is nothing to suggest that alcohol was a factor in the crash, according to Van Til.
The accident remains under investigation.
"He was just trying to do a good thing for somebody in need," the spokeswoman said.
"It's very sad. We have a job to do here, but sometimes it just brings you sadness."