Two three-vehicle crashes injured two drivers on Interstate 89 Tuesday morning.Vermont State Police said about 8 a.m., three vehicles were involved in a crash in the southbound lanes at the Winooski River Bridge.While troopers responded to the call, three other vehicles were involved in a second crash in the backup.At the second crash scene, one car caught fire and the driver had to be rescued. A trooper and a bystander pulled the driver from the car before it became fully engulfed in flames.Investigators said Tammy Thompson, 54, of Fairfax, was driving southbound in the left lane, south of exit 16, when vehicles ahead of her stopped due to the first crash.Thompson's 2011 Kia Soul rear-ended Danielle Houle-Charbonneau's 2013 BMW 328.The impact forced Houle-Charbonneau's car into the left guardrail and then into the back of a third vehicle, which was also stopped in the traffic backup.  Houle-Charbonneau, 45, of St. Albans, was trapped when her car caught fire and was rescued. Houle-Charbonneau and Thompson were transported to UVM Medical Center for treatment of injuries sustained in this crash. Houle-Charbonneau appeared to have suffered head injuries and Thompson appeared to have significant injuries to her legs.The third driver involved in this crash, Alan Gott, 67, of Georgia, was not injured in the crash.Water firefighters used to fight the car fire froze on the highway and state workers had to use salt to clear it before reopening the road.The highway was closed for almost two hours. No charges have been filed.Emergency personnel from Colchester Fire and Rescue, Winooski Fire, UVM Rescue, St. Micheal's Rescue, the Vermont State Police, as well as Colchester police, Winooski police, Chittenden County Sheriff's Office and Vermont Agency of Transportation responded to the crashes.The crashes remain under investigation.9233958