Troopers with the Michigan State Police had been stationed on Interstate 96, controlling traffic as workers installed power lines across the road, the department said in a statement.
Prior to the crash, "numerous" cars had come to a halt in the expressway's westbound lane near the intersection with M-52, police said. The work, which was being done by Consumers Energy, required the road to be completely shut down for a short period, police.
Those vehicles had just begun moving again when the truck crashed into them, police said.
"It appears the driver of the semi-truck did not see the backup and could not stop his vehicle in time," police said. "The semi-truck was in the left lane of travel and struck numerous vehicles."
The truck and more than a dozen other vehicles caught fire after the crash, police said.
"Seventeen vehicle occupants have been transported to UM Sparrow Hospital and McLaren Hospital in Lansing for serious injuries," police said.