Just last week, Eckert was at the White House with Barack Obama, part of a meeting the president had with relatives of those killed in the 2001 attacks and the bombing of the USS Cole to discuss how the new administration would handle terror suspects.
CBS News correspondent Michelle Miller reports that Mr. Obama remembered her today.
"She was an inspiration to me and to so many others. I pray her family can find peace and comfort," the president said.
"She was such an important part of all of our work," said Mary Fetchet, another 9/11 family activist. She learned Eckert was aboard the plane from another close Eckert family friend now headed to Buffalo. Officials investigating the crash have not yet confirmed she was on board the plane.
Eckert, who was flying to Buffalo to celebrate what would have been her husband Sean Rooney's 58th birthday, was one of the most visible, tearful faces in the aftermath of the terror attacks.
She carried that grief to Congress as she tried to make the government do a better job protecting its citizens from terrorism.
Her husband worked at Aon Corp., a risk management firm, at the 98th floor of the World Trade Center's south tower.
She cried when she would tell the story about how her husband - who was her high school sweetheart - called her on the morning of the attacks, and told her he loved her just before there was a loud explosion and nothing more.
Eckert was part of a small group of Sept. 11 widows, mothers, and children who became amateur lobbyists, ultimately forcing lawmakers in 2004 to pass sweeping reforms of the U.S. intelligence apparatus.
They spent months walking the halls of Congress. All of the women were grieving, but Eckert seemed unable or uninterested in holding back her tears.
When it was over and they'd won passage of the intelligence reform law, Eckert vowed to quit her high-profile role "cold turkey." All she wanted, she said, was to go home, buy groceries, and return to something like a regular life.
"I did all of this for Sean's memory, I did it for him," she said, crying again. "There is a euphoria in knowing that we reached the top of the hill. ... I just wanted Sean to come home from work. Maybe now, someone else's Sean will get to come home."
Eckert was flying to her hometown Thursday night when the .
Sixty-one-year old Douglas Wielinski was killed inside his home, reports Miller. His wife and daughter . Friday night, a somber community gathered at local church to remember their neighbor and those lost on Flight 3407.
Other Known Crash Victims Of Flight 3407:
These names have been provided by airline officials, relatives or friends.
"She absolutely loved to fly," said Lyn Morris.
Shaw graduated in 2002 from Tahoma High School, where she was active in volleyball, softball and student leadership, district spokesman Kevin Patterson said. She attended Big Bend Community College before transferring to Central Washington University in Ellensburg. She graduated in 2007 with a degree in flight technology, university spokeswoman Teri Olin said.
Des Forges was returning home to Buffalo after a trip to Europe, where she briefed diplomats on the situation in Rwanda and Africa's Great Lakes region, said Emma Daly, spokeswoman for Human Rights Watch. She sent an e-mail to colleagues from the airport before boarding the plane.
"She was working till the end," Daly said.
Des Forges had a "tremendous commitment to human rights and her tremendous principles," Daly said.
Miller reports she was flying home from Florida to visit her brother Chris, who described the emotional phone call he had to make to his parents.
"I heard my mother make a noise on the phone I have never heard before," Chris Kausener said.
Her sister, Laura Kausner, said Ellyce was flying home to be her nephew's date at a kindergarten Valentine's Day party on Friday.
Loftus' 22-year-old brother, Frankie Loftus, said his sister never worried about flying because their father was a pilot for Continental. He said he dropped her off at the airport Thursday.
"She was an amazing person. She loved to make everyone happy," he said. "Everyone who met her loved her instantly."
Loftus transferred to St. Mary's University in Minnesota after her sophomore year, Ventura said.
"We are heartbroken that someone so young and full of life could be taken from us so suddenly," Brian McDonald, the vice president of development at Princeton, said in a statement released by the university.
Maurer was traveling to New York to meet the family of her boyfriend, Kevin Kuwick, an assistant basketball coach at Butler University, The Buffalo News reported.
Maurer, who grew up in Sinking Spring, Pennsylvania, was a champion swimmer at Rowan University in Glassboro, New Jersey, where she graduated in 2001. She received a master's degree from the University of Florida.
An accomplished jazz guitarist, Mellett was a touring member of trumpeter Chuck Mangione's band for the last several years. The group was scheduled to perform Friday night at the Kleinhans Music Hall with the Buffalo Philharmonic.
Mellett grew up near Washington, D.C., and moved to New Jersey to study at William Paterson University, according to his MySpace profile. After graduating he moved to New York and earned a master's degree at the Manhattan School of Music in 1998.
Mellett, 33, lived in East Brunswick, N.J., with his wife, singer Jeanie Bryson, according to the Star-Ledger of Newark.