NEW CANAAN — A New Canaan father and his two children were arrested after a teen suffered a head injury at their Ponus Ridge Road home during an underage drinking party, police say.

The incident comes mere months after a father and son duo, Douglas and Andrew Knight, were charged after Douglas Knight prevented going partygoers from calling 911 after a 17-year-old boy was injured during an underage drinking party Andrew Knight threw at their Oenoke Ridge Road home.

On May 30 around 2 a.m., a 17-year-old girl arrived at Norwalk Hospital, drunk and suffering from a non-serious head injury. The girl was brought to the emergency room by her friends.

Staff at the hospital became aware the girl was injured at a New Canaan house party and contacted police who responded to the hospital to investigate. There they spoke with four teenagers who’d been at the party and came to Norwalk Hospital with the girl.

The teenagers told police they were classmates of Sophie Vos, 18, and had been at a high school graduation party at her house. The students had graduated the morning before from a private school in Newport, R.I. and then traveled to New Canaan. They were planning on staying over in New Canaan, as none of them lived in the area.

According to heavily redacted court filings, the teenagers told police they were partying outside the Ponus Ridge Road home and Vos’ parents were inside, but didn’t know the teens were drinking. The 17-year-old girl was injured when she was dancing in the back patio area and fell where there was a divot in the ground by a storm drain, according to court records.

The other partygoers were concerned about the 17-year-old’s medical condition, so they took her away from the backyard party to keep an eye on her. The girl’s state got worse and the teenagers texted someone to bring them to the hospital.

While police spoke with the teens, another officer went to the Vos’ Ponus Ridge Road home to speak with Sophie Vos, who allegedly knew about the drinking and the injury.

When the officer entered the backyard of the Vos’ home, he smelled alcohol and saw vomit covering several parts of the lawn and patio. Several cans of Mike’s Hard Lemonade and Budweiser were in garbage bags and there was evidence of beer pong being played, including an orange ping pong ball found on the ground.

Police were then advised there was potentially another injured teen inside the home. Officers entered the Vos home through an unlocked door. After announcing their presence, police met Jim Vos, 54, in the kitchen. When police explained to him why they were there, he said “Kids probably. I’m not going to answer any questions period.” He refused to cooperate further with the investigation.

Hayden Vos, son of Jim Vos, then entered the kitchen. The 22-year-old told police there had been a small party at their home with about 20 teens present. He also said he knew the injured teen. When asked if he’d seen the girl get injured, Hayden Vos told police “I was here while there was kids here. I didn’t see what happened, but something happened back there.”

The 22-year-old acknowledged that someone tripped and fell and he called someone’s parents, believing it’d be best if the girl went to the hospital. He also said his parents were asleep for most of the time the teens were at his home. Hayden Vos added he didn’t know who supplied the alcohol, as he wasn’t home, but acknowledged there was alcohol on the property.

Police asked if there were any other injured teens at the home, but the older Vos said he wasn’t answering any more questions. Hayden Vos then told police his sister fell during the party, but she didn’t suffer any serious injuries. Police asked if they could check on her, but the 22-year-old said she was sleeping. Neither Vos would allow police to wake Sophie Vos to have her come downstairs to answer questions and police were not able to speak with the 18-year-old to confirm her injuries.

After several weeks of investigation, police were able to obtain arrest warrants for Jim, Sophie and Hayden Vos. All three members of the Vos family surrendered themselves to police over the course of several days.

On June 26, Jim Vos turned himself into police on a charge of failing to halt the possession of alcohol by a minor.

On June 27, Sophie Vos surrendered herself on a charge of permitting a minor to possess alcohol.

On June 29, Hayden Vos turned himself in, also on a charge of failing to halt possession of alcohol by a minor.

All three parties posted a $2,500. They will each appear in Norwalk Superior Court, respectively, on July 10, July 11 and July 13.

ekayata@hearstmediact.com; @erin_kayata