Two men who lost 10 family members in last month's crash of Ethiopian Airlines 302 filed lawsuits Monday against The Boeing Co., manufacturer of the grounded 737 Max 8 aircraft, as well as administrative claims against the Federal Aviation Administration.

Two plaintiffs' law firms, Chicago's Clifford Law Offices and Cotchett, Pitre & McCarthy of Burlingame, California, announced the 10 lawsuits at a press conference held hours after Boeing CEO Dennis Muilenburg apologized to crash victims and attempted to assure shareholders about the safety of its aircraft while skirting calls for his resignation.

“I, like many of you today, listened to Boeing and their CEO say as he began his press conference that he was sorry,” said Frank Pitre, of Cotchett Pitre. “And I think what we've heard today is there's a lot to question about the sincerity that Boeing has when it uses the words, 'I'm sorry.' If you look at the actions of Boeing, it portrays a very different picture.”

He continued: “I question, and I think these families here today, the sincerity behind the words 'I'm sorry.'”

Pitre called on Boeing's entire board to resign, and for Congress to investigate “serious problems” at the FAA.

The lawsuits involved two Canadian families in the Toronto area: Manant Vaidya, who lost his parents, his sister, her husband and their two children in the crash, and Paul Njoroge, whose wife and three children, including a 9-month-old daughter, died in the crash.

Both gave tearful statements at Monday's press conference.

“It is hard to believe that my entire family was wiped out in an incident in such a horrific way,” Vaidya said. “I lost three generations of my family: my parents, my sister, my nieces. If a person just lost one life, their whole life is shattered, but right now, with me, I'm completely lost.”

Vaidya's family was on vacation, while Njoroge's had planned to visit extended relatives in Kenya.

“I was left alone to lead an empty life, with pain and anguish. My life will never be the same,” Njoroge said. His other children were ages 6 and 4.

The Ethiopian Airlines flight, which killed 157 people on board after nosediving soon after takeoff, was the second involving the 737 Max 8. An Oct. 29 crash of Lion Air Flight 610 in Indonesia killed 189 people. The FAA grounded the aircraft days after the Ethiopian Airlines crash, but after 22 other countries had done so.

Earlier this month, the same two law firms filed a lawsuit on behalf of Samya Stumo, a U.S. passenger on the plane and niece of consumer advocate Ralph Nader.

Other lawsuits have been filed against Boeing over the Ethiopian Airlines crash, including one by another firm, Kline & Specter in Philadelphia, on behalf of the estate of Manisha Nukavarapu, a citizen of India. In a footnote in that lawsuit, Kline & Specter indicated it planned to bring an administrative complaint against the FAA.

Boeing became an immediate target following the crash. Lawsuits have linked the crashes to the Maneuvering Characteristics Augmentation Systems, or MCAS, an automated safety mechanism designed to prevent stalling that, under certain conditions, could push the aircraft into a nosedive. Monday's lawsuits also named Rosemount Aerospace Inc., a Minnesota-based unit of Farmington, Connecticut's United Technologies Corp. that manufactured the sensors.

In its quarterly report filed last week with the U.S. Securities and Exchange Commission, Boeing acknowledged the suits filed over both crashes and added, “we are fully cooperating with all ongoing governmental and regulatory investigations and inquiries relating to the accidents and the 737 MAX program.”

Lawsuits also insisted Boeing failed to property train pilots on the new software. Boeing originally had planned to complete a software upgrade by April but has since given no schedule on the fix.

Earlier this month, Boeing issued a statement: “We now know that the recent Lion Air Flight 610 and Ethiopian Airlines Flight 302 accidents were caused by a chain of events, with a common chain link being erroneous activation of the aircraft's MCAS function. We have the responsibility to eliminate this risk, and we know how to do it.”

Boeing continued: “We're also finalizing new pilot training courses and supplementary educational material for our global MAX customers. This progress is the result of our comprehensive, disciplined approach and taking the time necessary to get it right.”

But on Monday, Muilenburg “changed his tune,” Clifford Law's Kevin Durkin said, noting that the CEO had refused to answer whether Boeing was at fault.

“We are going to seek every single email, text message, that was between them and the FAA,” Durkin said Monday. “It will be our goal in this lawsuit to take that CEO's deposition, ask him questions about his 'shifting positions' on accepting responsibility for this tragedy.”