DENTON, Texas (KWTX) – Severe storms on Monday morning closed two major highways in North Texas. The southbound lanes of I-35 are shut down at Milam Road in Denton after two 18-wheeler trucks were blown over. The Denton Police Department said one of them, a Walmart truck, landed on a pickup truck. It happened sometime after 9 a.m. Monday, when a squall line bringing strong wind and gusts was blowing through the area.