Thursday, relatives of Rwandan man and United Nations employee Jackson Musoni filed a wrongful death lawsuit in United States federal court in Chicago against the airframe company Boeing. Musoni was one of 157 people killed March 10 when an Ethiopian Airlines Boeing 737 MAX Flight 302 crashed on a runway in Addis Ababa during takeoff.

As stated in the lawsuit, Boeing produced planes with defective automated flight control systems. The Ethiopian Airlines plane crashed after its autopilot erroneously told the flesh-and-blood pilots that the plane’s nose was too far up, threatening a stall. The system over-corrected, sending the plane nose-down back into the ground. This was the second such crash in five months, with an Lion Air craft in Indonesia having gone down in October 2018, killing 189.

“Boeing negligently failed to warn the public, the airlines, the pilots, the users, and the intended third-party beneficiaries of the 7387 Max 8’s unreasonably dangerous and defective design,” read the lawsuit, “including that the aircraft automatically and uncontrollably dived partly because of erroneous sensors.”

“Boeing, having knowledge of all the reports of dangerous conditions and the previous accident that killed over 150 people, should have taken steps to protect the flying public,” said the Musonis’ lawyer Steve Marks. “This accident happened when it should have never happened.” Boeing also announced a design change to the 737 MAX: It has reprogrammed the automated flight system, and an additional warning system is to be sold standard instead of as an option.

In the United States, congressional hearings on the Federal Aviation Administration’s oversight of the 737 MAX began on Wednesday, part of a series of investigations into the approval of the 737 MAX for use that also include the Justice Department and Department of Transportation. The 737 MAX is Boeing’s newest plane, having begun use in 2017.

Boeing declined to comment on the lawsuit but Boeing CEO Dennis Muilenburg spoke more generally of the crashes earlier this week: “Since the moment we learned of the recent 737 Max accidents, we’ve thought about the lives lost and the impact it has on people around the globe and throughout the aerospace community. All those involved have had to deal with unimaginable pain. We’re humbled by their resilience and inspired by their courage.”