Maintenance technician killed by robot at Ventra Ionia auto parts plant

What happened

Ventra Ionia Main, an affiliate of auto supplier Flex-N-Gate, made bumpers, trailer hitches and plastic parts in Ionia, about 130 miles west of Detroit. One line used robots to assemble and weld trailer hitch receiver assemblies and was divided into zones separated by safety walls and doors.

At about 2:20 p.m. on Tuesday, July 7, 2015, the Ionia Public Safety Department was told that an employee was trapped in machinery. Officers and coworkers freed her, and she was pronounced dead at the plant. She was a 57-year-old journeyman maintenance technician.

Accounts of how it happened differ. The lawsuit filed by her husband in 2017 alleged that she was inspecting machinery in one section when a robot from a neighboring section entered unexpectedly and crushed her head between a hitch assembly it was loading and one already in the fixture, and that safety doors meant to stop robot movement did not work. A federal court’s September 2021 opinion, as described in a legal commentary, said that workers were supposed to press a button, wait for a green light and lock the zone door open before entering, which would power down the robots in that zone. According to that account, she instead climbed over a wall, and a robot from another section, operating as programmed, entered the zone and crushed her.

The system involved

The line was designed, built and installed by Prodomax Automation, with robots supplied by other manufacturers. Each zone had an entry procedure that removed power from the robots in that zone. According to the 2021 court account, the robot that struck the technician came from an adjoining section and was following its program. The line was later reprogrammed so that all robots powered down whenever a zone door was opened.

Investigation and response

The Michigan Occupational Safety and Health Administration investigated. In January 2016 the Associated Press reported that state regulators had proposed a $7,000 fine and that inspectors said a lockout device could have halted the machine when the technician entered the robotic cell. The plant’s general manager declined to comment. Ventra settled a workers’ compensation claim related to the death in 2016.

In March 2017 the technician’s husband sued six companies in federal court in western Michigan, including Prodomax, Flex-N-Gate and robot manufacturers. In November 2020 the court declined, for the time being, to dismiss Flex-N-Gate on workers’ compensation grounds. In September 2021 the court ruled on summary judgment motions. The robot manufacturers had already been dismissed and Flex-N-Gate was dismissed; common-law negligence claims were held to be displaced by Michigan’s product liability statute; and a design-defect claim over the line’s programming went forward against Prodomax. The court found that climbing the walls was a foreseeable misuse. Bloomberg Law reported on November 9, 2021, that the estate and Prodomax reached a confidential settlement in the middle of trial.

What is not established

The lawsuit’s account and the court’s later account of how the technician came to be in the robot’s path differ, and no public investigation report resolving the point was located. Whether Ventra contested the proposed state fine, and the terms of the 2021 settlement, are not known. No appellate decision in the case was located.