Police say that alcohol is a factor in a crash that killed two teens and left another with critical injuries early Saturday morning in Brantford, Ont.

The Ontario Provincial Police says that Carin Milmine, 17, and Shawn McLaughlin, 18, died after they were hit by an SUV around 1 a.m.

On Saturday afternoon, their 19-year-old friend, Kelly Myers-Gordon, was in serious condition at the Hamilton Health Sciences Centre.

A fourth person, Kristynn Harrot, 17, was also in a Brantford hospital, but her injuries were not described as life-threatening.

Police say the teens were hit as they were stepping into a parked vehicle after attending a party on Burtch Road.

OPP Const. Larry Plummer told ctvtoronto.ca that the teens were partying at a nearby house and were about to be driven home by a designated driver.

Plummer added that the designated driver had already taken home one carload of teens and was about to make his second trip of the night when the crash occurred.

"He had already done one pick-up, and he was back for his second run," Plummer said.

The designated driver wasn't seriously injured.

A 17-year-old male from nearby Six Nations has been arrested in the crash. He faces several charges but cannot be named because of his age.

Police had been called to the Burtch Road home because of a noise complaint, and they arrived at the scene just after the crash.

Officers were then able to stop the suspect about a kilometre away from the crash site, where they found damage to the SUV he was driving.

Officers are piecing together the crash and they believe that the suspect was drinking earlier in the night.