"The whole thing is a parent's nightmare," said local resident Rowdy Metzger, who found the boy.
Police said Kurihara left his son Dylan Kurihara inside his Lexus SUV. He was at a wedding at a Pasadena Masonic temple with his son Saturday night, where he allegedly got drunk, put his 3-year-old inside the SUV and walked away.
About an hour later, he was stopped by police for public intoxication while walking along Green Street. By Sunday morning, the child's mother called police to report her boyfriend and their child missing.
Police told the mother that Kurihara was in custody, but they had not seen the boy. When police asked Kurihara, he told police he had left his son in his parked car, but he didn't know where.
"Apparently, he was intoxicated to the point that he didn't remember where he had parked the vehicle, where the child was," said Sgt. Ed Calatayud of the Pasadena Police Department.
Using the reverse-911 system, Pasadena police notified 90,000 residents of the missing child. Metzger, a father of two, said when he heard about the missing child, he felt compelled to help.
"My wife said, 'You can either sit here and brood about it or do something about it,'" he said.
Metzger set out to look for the child, and he was in luck. He spotted the SUV and the little boy in a parking garage at about 10:40 p.m. Sunday.
"The doors were open, so I got in, I said, 'Are you Dylan? I'm here, I'm going to help you out, you want to come with me?'" Metzger said. "He just was motioning that he wanted out."
The boy was scared and dehydrated, but authorities said it could have ended much worse.
"Had we had a hot summer day, things could have been a lot more tragic than the result," Calatayud said.
The boy was treated at Huntington Memorial Hospital and released. He has been placed in the custody of child protective services.
Police said the boy's mother was also at the wedding, but it's unclear if she knew her boyfriend was drunk when he left the event.