BOULDER, Colo. Two people were killed and two others were injured in a single-vehicle rollover crash on Highway 36 in Boulder on New Year's Day, troopers with the Colorado State Patrol said.Troopers responded to the crash on Highway 36 at Lefthand Canyon Dive at around 9:46 a.m. and confirmed that a Jeep heading north on the highway traveled through the center grass median before rolling and coming to rest in the southbound lanes of the highway, according to a news release.Two adults, the driver and a passenger, were killed on impact, troopers said, and two other passengers both children ages 11 and 16 were taken to a hospital with moderate injuries. Troopers said the highway was initially closed in both directions between Nelson and Neva Roads but lanes in both directions have since reopened.This remains an active investigation, with investigators still on scene. All possible causes for this crash are still under investigation, troopers said.The identities of the deceased will be released by the Boulder County Coroner once family has been notified.