(NDTV) A screw-like device found in the wreckage of the Boeing 737 Max that crashed last Sunday in Ethiopia indicates the plane was configured to dive, a piece of evidence that helped convince U.S. regulators to ground the model, a person familiar with the investigation said late Thursday night.

Federal Aviation Administration chief Daniel Elwell on Wednesday cited unspecified evidence found at the crash scene as part of the justification for the agency to reverse course and temporarily halt flights of Boeing’s largest selling aircraft. Up until then, American regulators had held off as nation after nation had grounded the plane, Boeing’s best-selling jet model.

The piece of evidence was a so-called jackscrew, used to set the trim that raises and lowers the plane’s nose, according to the person, who requested anonymity to discuss the inquiry.

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