Honey Boo Boo's family dun caused the car crash that left several members of the reality bunch injured ... law enforcement tells TMZ.
The Milledgeville Police Department tells us ... investigators have determined Sugar Bear is to blame for the January 6th accident, because Sugar was behind the wheel and made an unsafe left turn in front of a truck when the two collided.
We're told ... the Boo Boo family admitted to seeing lights on the other vehicle, which means the burden to make a safe turn was on Mr. Bear.
Despite being placed with the blame, Sugar Bear won't be charged with a crime -- it's now a civil issue that the insurance companies will handle.
As for the Boo Boo family, everyone in the SUV -- Honey, Pumpkin, Mama June and Sugar Bear -- have been released from the hospital.
The SUV was towed from the scene ... still unclear if it'll ever run again.