A 22-year-old Texas mother has been missing for a week after a hit-and-run crash stranded her car on one of the longest bridges in America, and investigators still cannot explain how she disappeared. Christin Munn-Holliday, known to loved ones as "Chrissy," was last confirmed alive in the early hours of Sept. 30 on the Atchafalaya Basin Bridge, the 18-mile span that carries Interstate 10 over the Louisiana swamp between Baton Rouge and Lafayette.

Louisiana State Police say Munn-Holliday, of the Katy area near Houston, was driving a gray late-model BMW when it collided with another vehicle on I-10 eastbound near milepost 128 in Iberville Parish. When troopers and Iberville Parish deputies arrived, they found one occupied vehicle and a second car, empty, that belonged to her. Witnesses reported seeing her walk away from the wreck on foot. Her cellphone has not been located since, and her last known ping placed her near a gas station in Lafayette, according to WAFB.

"It wasn't random"

Munn-Holliday had dropped her 4-year-old son off with her parents on Sept. 29 and headed toward Louisiana, telling her father only that she was going, not why. Her mother said Munn-Holliday had shared her phone location with her before leaving, and that calls and texts sent around 2 a.m. never went through. By Oct. 1, Louisiana troopers learned she'd already been reported missing to the Harris County Sheriff's Office, which remains the lead agency on the case while Louisiana authorities investigate the crash itself.

"IT WASN'T RANDOM," her father, Robert Munn, told WBRZ, adding that someone either took his daughter or hurt her — and that the bridge isn't a place a person can simply walk away from unseen.

A law enforcement source quoted by WBRZ, identified only as "Stassi," called it "a very strange case" and said detectives have not ruled out that Munn-Holliday was picked up against her will. The family says traffic camera footage shows her driving at high speed across the bridge beforehand and believes she may have been fleeing another vehicle on I-10.

On Monday, detectives from multiple agencies returned to the crash scene, reducing eastbound I-10 to one lane while they searched the shoulder for evidence, according to KPRC Click2Houston. Volunteers with the United Cajun Navy have since launched boats and drones over the surrounding bayous and swampland, a search area spanning roughly 18 miles. "We're doing our best," volunteer Josh Gill said, adding that the group "made a promise to that family" to help bring her home.

Munn-Holliday is described as 5-foot-6 and about 120 pounds. Her family has offered a $20,000 reward for information leading to her safe return. Both the hit-and-run and missing-person investigations remain active, Louisiana State Police said, and anyone with information is urged to call the Iberville Parish Sheriff's Office or Crime Stoppers at 225-344-STOP.