Family members of victims of a 2019 crash of a Boeing Co. 737 Max in Ethiopia renewed calls for the ouster of U.S. aviation regulators as they met with top transportation officials.

A letter signed by 900 people called for Federal Aviation Administration chief Steve Dickson and three other top officials to be replaced, according to a press release issued by the group. Family members met with Transportation Secretary Pete Buttigieg, Dickson and others on Wednesday.

While a report on the Ethiopian crash hasn’t been finalized, multiple reviews have found that a design flaw in the plane that was missed by the FAA—in part because changes weren’t fully disclosed by the company—helped lead pilots to lose control. The FAA oversaw an extensive redesign of the plane.

Dickson took over the FAA after the two Max crashes, which killed 346, and played no role in the plane’s certification.

The release was emailed by the spokeswoman for the legal team suing Boeing on behalf of the families, which could win hundreds of millions of dollars.