A truck driver is dead after passing out behind the wheel during a medical emergency and causing a chain reaction crash. 

The accident happened in Far Northeast Dallas, Texas at the intersection of Plano Rd. and Miller Rd. just before 12:30 p.m. on Monday afternoon, July 21st. 

According to Fox 4 News, the truck driver was operating the flatbed tractor trailer hauling pipes when they passed out behind the wheel. The flatbed semi truck then crashed into a second semi truck, a car, a bus, and a box truck. 

A total of seven people were injured in the crash. Five of those victims sustained non life threatening injuries, and one was determined to be in critical but stable condition. The truck driver died at the hospital. 

The crash is still under investigation, but police officers believe that the truck driver suffered a medical emergency, leading to his passing out behind the wheel, which caused the crash.