ST. LOUIS COUNTY, Mo. – New details have been released following a fiery crash in Florissant Monday morning where a 13-year-old driver survived but three other children were killed. The 13-year-old driver is being held at the St. Louis County Family Courts on three counts of involuntary manslaughter.

Investigators with the Florissant Police Department revealed Thursday that the vehicle in this incident was a 2011 Ford Expedition that was decommissioned from the Hillsdale Police Department K9 unit. The vehicle was sold by the Hillsdale Police Department to a tow company where it was purchased legally by a family member of the driver. It still had the K9 partition at the time of the crash. The family member was not aware the vehicle was taken by the driver prior to the crash.

The investigation also revealed Thursday that the 13-year-old driver and the 9-year-old passenger were cousins who lived together. The other two 13-year-olds who were killed were not related.

The Florissant Police Department said, “speed and inexperienced driving” were contributing factors in this crash.

Police said the names of those involved will not be released.