CHICAGO (AP) — A Chicago law firm has taken steps to sue Boeing Co. on behalf of 83 people who were aboard the Asiana Airlines flight that crash-landed in San Francisco earlier this month, alleging that a malfunction of the plane’s auto throttle may have caused the crash.

Ribbeck Law Chartered on Monday filed a petition for discovery, which is meant to preserve evidence, in Cook County Circuit Court in Chicago, where the aircraft manufacturer is headquartered. The firm said in a news release that additional pleadings will be filed against Asiana Airlines and several component parts manufacturers in coming days.