WASHINGTON (CNN) August 2002 -- Acknowledging the odds are against them, relatives of the September 11 attacks filed a 15-count, $116 trillion lawsuit Thursday against the company run by Osama bin Laden's family, Saudi Arabian princes and Sudan.

The lawsuit was filed in U.S. District Court for the District of Columbia by more than 600 family members, plus some firefighters and rescue workers.

Calling themselves Families United to Bankrupt Terrorism, the plaintiffs are suing seven international banks; eight Islamic foundations, charities and their subsidiaries; individual terrorist financiers; the Saudi bin Laden Group; three Saudi princes; and the government of Sudan for allegedly bankrolling the terrorist al Qaeda network, Osama bin Laden and the Taliban.

The Saudi bin Laden Group is the construction company operated in Saudi Arabia by Osama bin Laden's brothers. Fifteen of the hijackers were Saudi Arabian, the FBI has said.

Deena Burnett, whose husband, Tom, was killed on hijacked Flight 93, which crashed in Pennsylvania, expressed optimism about the challenge at a news conference.

"It's up to us, and I think we can do it," she said. "It's up to us to bankrupt the terrorists and those who finance them so they will never again have the resources to commit such atrocities against the American people as we experienced on September 11."

Co-lead counsel for the lawsuit is attorney Allen Gerson, one of the attorneys who negotiated a $2.7 billion settlement between the Libyan government and families of 270 people killed when Pam Am Flight 103 was blown up over Scotland in 1988.

Among the allegations in the complaint, said attorney Ron Motley, are that certain members of the Saudi royal family have been active supporters of and helped fund al Qaeda and bin Laden.

The attorneys and investigators were able to obtain, through French intelligence, the translation of a secretly recorded meeting between representatives of bin Laden and three Saudi princes in which they sought to pay him hush money to keep him from attacking their enterprises in Saudi Arabia, Motley said.

Burnett's father in law, Thomas E. Burnett Sr., who also spoke at the news conference, said the group was "taking unprecedented legal action against those whose money financed the unspeakable evil that occurred on that tragic day."

Matt Sellitto, whose 23-year-old son Matthew died at the World Trade Center, told reporters: "His loss is incomprehensible to me. My heart continues to ache and will ache for the rest of my life."

"If the odds are stacked against us, we will beat them," Sellitto said. "And we will pursue this action until justice is served and terrorism is stopped."

Matthew Sellitto worked at the Cantor Fitzgerald brokerage house on the 105th floor of One World Trade Center.

-- CNNfn Correspondent Allan Dodds Frank contributed to this report.