The family members of two men killed in the first crash involving a new civilian helicopter model have filed a wrongful death lawsuit, alleging that defects in the engine and fuel system caused a mechanical malfunction soon after takeoff.

The suit, filed on Tuesday in Los Angeles County, Calif., Superior Court, came as the same attorneys evaluated potential litigation stemming from Saturday’s crash of Asiana Airlines Inc. Flight 214 in San Francisco. Officials with the U.S. National Transportation Safety Board are investigating that crash, which killed two and injured 181 from among the 307 crew and passengers on board the Boeing 777.