CLAVERACK — Four people died and two people, including a 1-year-old child, were in critical condition after a head-on collision in Claverack on Monday night, according to Columbia County Sheriff Jackie Salvatore.

The two-car accident on state Route 9H, just south of Van Wyck Lane, was reported to police just before 7 p.m. Monday, according to a statement from Salvatore’s office late Tuesday morning.

The accident happened when 2009 Toyota Prius, driven by a 29-year-old Loudonville man, who police did not name, was driving north on 9H and crossed over into the southbound lane for unknown reasons, hitting a 2025 Toyota Crown head-on, according to the sheriff’s office.

The 29-year old driver of the Prius, who police did not name, was pronounced dead at the scene, according to sheriff’s office.

The Prius had four passengers, including a 60-year-old man and a 25-year old man, who police did not name, who were both killed in the crash and pronounced dead at the scene.

A 33-year-old woman and a 1-year-old girl, who were also passengers in the Prius, were critically injured in the accident. The woman was transported by ambulance to Albany Medical Center, while the 1-year-old girl was transported to Albany Medical Center by a LifeNet helicopter. Both remained in critical condition Tuesday morning, according to the sheriff’s office.

The 24-year-old Brooklyn man, who police did not name, driving the Toyota Crown was taken to Albany Medical Center by ambulance for medical treatment and was released. The other occupant of the Toyota Crown, a 62-year-old woman, who police did not name, was also pronounced dead at the scene, according to the sheriff’s office.

The accident left state Route 9H closed for four hours and it remains under police investigation, according to the statement.

In addition to sheriff’s deputies, New York State Police, A. B. Shaw Fire Company, Livingston Fire Company, Greenport Rescue Squad, Valatie Rescue Squad, Chatham Rescue Squad, LifeNet and Columbia County Coroner’s Office personnel responded to the scene and are assisting with the investigation.