"A few weeks ago, we got the awful news that my now father-in-law was tragically killed by a drunk driver on his beloved Sunday motorcycle ride. Words can't explain the feeling of losing someone to something so senseless... something that could have been prevented," Parrish wrote on Instagram, alongside two family photos.
Parrish also urged her fans to learn about his life and donate to Mothers Against Drunk Driving.
"Please read about his life, and if you're moved by his story, help donate to MADD to help make sure this doesn't happen to anyone else. Link in my bio. Love you Buck," she continued.
According to the Highland Community News, Long, 74, was killed on Sunday, Aug. 26. He was struck by a Ford Mustang, driven by 18-year-old Miguel Ochoa Torres, who tried to flee the scene. A 26-year-old passenger in the Mustang was treated for injuries at a nearby hospital. Ochoa Torres was later arrested and booked for "felony hit and run, felony driving under the influence and gross vehicular manslaughter."
Long was a member of the U.S. Navy and served on the U.S.S. Kearsarge, the aircraft carrier that recovered the last two Project Mercury space missions, according to his obituary.
"Those that knew him will tell you he was the youngest and healthiest 74-year-old anyone has ever met. He will be sorely missed by all those whose life he touched," the obituary reads.
Parrish and Chris became engaged in October 2017 and married on Sept. 9 in Hawaii. On Sept. 12, Chris shared photos from the wedding on his Instagram page, adding the caption, "Just married the love of my life and making Pops proud."
"We feel so lucky we found each other in this crazy world," Parrish told Us Weekly after the wedding. "Marrying my dream man in my home of Hawaii surrounded by family and friends was a dream."
Parrish also called Chris her "best friend in the entire world," adding, "No matter what, if I'm having the worst day ever, I feel like I have somebody who understands me. And even if he doesn't quite understand me at that moment, he tries to... And that feels so nice."
Parrish played Mona Vanderwaal on Pretty Little Liars and recently starred in Netflix's To All The Boys I've Loved Before. She plays Mona again in Freeform's upcoming spinoff series Pretty Little Liars: The Perfectionists.
Photo credit: David Mendez/Young Hollywood/Getty Images