The fiery multi-car crash that killed four people in Thornton on Saturday was caused by a rear-end collision at a red light, police said. A Ford SUV carrying four people was traveling northbound on Washington Street when the driver stopped at a red light at Thornton Parkway, according to a Tuesday news release from the Thornton Police Department. Police said the driver of the second car, a Subaru sedan, was speeding down northbound Washington Street when it crashed into the back of the stopped SUV around 7:30 p.m. Saturday. The crash caused the gas tank to rupture, lighting the SUV on fire. A third car, a Chrysler van, was also struck in the crash, police said. The driver was not injured. Police said the car fire killed the two adults and two children inside the SUV. The four were declared dead at the scene of the crash but have not been publicly identified. Their identities will be released at a later date by the Adams County Coroner’s Office. Related Articles Crashes and Disasters | Westbound I-70 reopens after crash near Frisco Crashes and Disasters | 4 killed in fiery two-car crash in Thornton Crashes and Disasters | Pedestrian killed in fatal Denver crash Crashes and Disasters | Colorado alpinist dies challenging unclimbed face of Himalayan peak Crashes and Disasters | Southbound I-25 reopens in Colorado Springs after crash Paramedics took the driver of the speeding Subaru to the hospital with “serious” injuries, according to the news release. No update on the driver’s condition was available Tuesday. This is a developing story and may be updated.  Sign up to get crime news sent straight to your inbox each day.