The family of Samya Stumo has been brought to tears and forced to action, they say.
"That’s why I am crying, because its horrible," Stumo's mother, Nadia Milleron, said. "Its not like there was an accident, this was not an accident. This is something that could have been prevented."
The 24-year old Massachusetts woman was among the 157 people killed when an Ethiopian Airlines 737 Max 8 crashed last month shortly after takeoff from Addis Ababa.
The federal lawsuit filed Thursday in Chicago alleges that Boeing was aware of problems with the plane’s flight control system, known as MCAS, but pressured the Federal Aviation Administration to speed up its approval process.
Noted consumer advocate Ralph Nader phoned in to Thursda's news conference. He was Stumo’s great uncle.
"Those planes should never fly again," he said. "Those planes, the 737 Max 8, must be recalled."
The lawsuit was announced on the same day that the preliminary report on the crash was released by Ethopian authorities.
They say the crew followed procedures but that a faulty data sensor may have triggered the crash.
In a company video, Boeing’s CEO, Dennis Muilenburg, promised that problems with the plane will be fixed.
"Together we will do everything possible to earn and re-earn that trust from our customers and the flying public in the weeks and months ahead," he said.
But for Stumo's family, like her brother Adnaan, that trust will be hard to restore.
"You’ve let us down," he said. "You’ve killed people. This whole 'fool me once, fool me twice,' there's no third crash. There can’t be a third crash."