Prasad Moparti attended a wedding reception last weekend in Northern California - a joyous event celebrating his daughter's marriage.
But he walked away from the party in the Sacramento River Delta, authorities say, and hasn't been seen since.
Moparti, 55, disappeared from the reception at Grand Island Mansion, on the Steamboat Slough, on Saturday afternoon, according to the Sacramento County Sheriff's Department.
He was reported missing by relatives, who told authorities that he had left on foot and never returned.
"Our only focus is to get our father back," Moparti's daughter, Durga, told a local Fox affiliate. "And our efforts will continue until we get our father back."
Sheriff's officials searched for three days for Moparti, who came to the United States from India last month and isn't particularly familiar with the area, according to the sheriff's department.
On Tuesday night, the search was suspended indefinitely. "All resources were utilized to search for Moparti on the ground, water, and from the air with no results," the sheriff's department said.
Moparti is considered "a voluntary missing person," according to the sheriff's office.
"There's no indication of any foul play or suspicious circumstances whatsoever," Sgt. Tony Turnbull, a sheriff's department spokesman, told The Washington Post.
Investigators believe that Moparti was suffering from "some kind of depression," Turnbull said, adding that Moparti's family had noticed some troubling behavioral indicators.
Durga Moparti described her father in somewhat different terms during her interview with the Fox affiliate, saying he was an active participant in the wedding events.
"I believe that he was just walking and he fell unconscious, and he just tripped or something like that," Durga told the station. "But I'm really not sure what happened, and this seems like a total mystery."
She echoed that sentiment in an interview with the Sacramento Bee, which reported "that she cannot comprehend a scenario in which her father would vanish. There was no indication that her father was upset."
At the wedding itself, "our dad was really very happy," she said, according to the Bee. "He was dancing. He was really joyful."
Moparti was last seen at the mansion in Walnut Grove, wearing traditional clothing, with a top in colors of brown and gold.
"My dad missing is the only thing going on in my head right now," Durga Moparti told a CBS affiliate. "Nothing else."
On Tuesday, hours before the search was called off, she still sounded hopeful, according to the Bee.
"We are pretty positive we will be able to find him soon," she said. "We are hoping for some miracle at this point."