She boarded Flight 77 with several children from her sixth-grade class at Backus Middle School in Washington. They were on a class trip to Santa Cruz, Calif., said her close friend John Milton Wesley, 52, a spokesman for the Housing Authority of Baltimore City.
"She was originally supposed to go to Florida, but two weeks ago they changed it and told her she was going to California," Mr. Wesley said from the Columbia home he and Ms. Clark shared. The couple had recently returned from a long vacation and Ms. Clark wanted a break from traveling, he said.
Mr. Wesley said Ms. Clark loved children. The couple spent part of Saturday sorting books they had collected for children living in public housing and for students at Backus Middle School.
"The best way I can describe her is she saw the same old world each day with new eyes, and her compassion never blinked," he said.
Ms. Clark earned a bachelor's degree in elementary education from North Carolina's Winston-Salem Teachers College, now Winston-Salem State University, in 1962, and a master's degree in special studies and urban learning from George Washington University in 1975.
She leaves a daughter in Laurel and a son in Denver.
Though he continues to watch news accounts of the terrorist attack, Mr. Wesley said he isn't concerned about the investigation into who is to blame.
"That has no collateral value for me," he said. "The only thing I can reflect on is what we had and how much she affected my life. She made me so much of a better person, a better man."
-- Laurie Willis
Zoe Falkenberg, 8, was a soccer player and talented singer who appeared in a community musical production. Dana Falkenberg, 3, was in pre-school.
The family had just sold their University Park home and were traveling to Australia for Ms. Whittington's sabbatical.
Ms. Whittington, 45, was a longtime University of Maryland educator who became an associate professor of public policy at Georgetown in 1997. Colleagues called her a popular teacher with an active interest in tax policies and the status of women in industrialized and developing countries.
Mr. Falkenberg, 45, was the director of research at ECOlogic Corp. in Herndon, Va. He had recently completed a study of the Exxon Valdez oil spill that found lasting repercussions a decade afterward, according to company spokeswoman Chris Dooley.
Ms. Whittington was the co-author of several papers with James Alm on the effects of taxation on marital decisions, including a 1998 study that found the federal government would gain substantial revenue if same-sex couples were permitted to marry.
Mr. Alm, a Georgia State University professor and a family friend, described Ms. Whittington as "funny, quick-witted and loyal and warm." He said she was a skilled skier and an enthusiastic cook.
Mr. Falkenberg left college to found a computer business but later earned undergraduate and graduate degrees from the University of Maryland, Mr. Alm said.
"He was very cerebral in an engaging way," he added.
Mr. Falkenberg and Ms. Whittington "were not only very good neighbors but very good citizens of the community," said University Park Mayor John L. Brunner, who lived across the street from the family.
The family had planned to move to Chevy Chase after their return from Australia in November.
-- Michael Dresser
She was the oldest of three children and grew up in California. Barbara J. Strong, her aunt, said Ms. May, 39, had been a flight attendant for about 10 years.
Terri O'Heir, an American Airlines flight attendant who lives in Stoneleigh, said Ms. May was "just someone you always liked to see."
"She was lovely. You knew flying with her you were flying with a professional," Ms. O'Heir said.
Gary Vikan, director of the Walters, said he first met Ms. May as a student in a continuing studies course at the eight or nine years ago. She subsequently became a docent at the museum, leading tours for schoolchildren. She often wrote Mr. Vikan detailed messages on issues affecting the museum.
"She was a very quiet, very rare kind of person with wide-ranging interests," said Mr. Vikan, adding that Ms. May was also active in protecting the rights of flight attendants. He said that she once asked him to sign a petition on that issue, which he did.
A friend of Ms. May's told the museum of her death shortly after noon yesterday, said Mr. Vikan.
"Everyone was crying," said Mr. Vikan. "This just sent everyone into shock."
Neighbors described her as an outgoing person who opened her home to children and loved neighborhood get-togethers.
"She was the type of person that would talk to everyone," said Millie Bratcher, 37, who lived two doors away from Ms. May. "She always had a smile on her face."
Mildred Colwell, Ms. Bratcher's mother, said Ms. May would give her a bottle of wine as a present for taking in her packages when the attendant was out of town.
"I said, 'Renee, I don't want nothing.' But she insisted," Ms. Colwell said.
Neighbors said Ms. May had a serious boyfriend who had helped her make some repairs on her house over the weekend.
"He came by [yesterday] to pick up the mail," said Sharon Mondshour, who lives across the street.
-- Eric Siegel and Walter F. Roche Jr.
Mr. Yamnicky had worked for Veridian Corp., a defense contractor, since his retirement as a captain in 1979. He was working with military aircraft and weapons systems, said his son, John, 39.
Mr. Yamnicky was en route to California on a business trip, his son said. He took Flight 77 to California several times a month.
"He never talked about his work," said Cindy Sharpley, who has known the Yamnicky family for about 20 years.
But Mr. Yamnicky, a 1952 graduate of the U.S. Naval Academy who became a Navy test pilot, flying an A-4 attack plane, would sometimes tell stories from his travels and Navy service in Korea and Vietnam.
"He crash-landed five times and walked away from them each," Ms. Sharpley said. "But not this last one."
Mr. Yamnicky graduated from the Navy Test Pilot School at Patuxent River in 1960.
"He had done a number of black programs -- which means top-secret," said his son. "We were given no details."
Mr. Yamnicky worked on the development of the F/A-18 fighter jet, said his son.
Mr. Yamnicky, who served on aircraft carriers, became a captain in 1971, when he was stationed at Patuxent River, then worked the office of the Secretary of Defense. Among the many decorations displayed on the walls of his Waldorf home, Ms. Sharpley said, are the Defense Superior Service Medal, Distinguished Flying Cross, Combat Action Ribbon and the Navy Expeditionary Medal.
A native of Barren Run, Pa., Mr. Yamnicky received a master's degree in international relations from George Washington University in 1966.
He is survived by his wife, Jan; four children; and eight grandchildren.
-- Michael Scarcella
The society was sending him, two other Washington teachers and three students to the Channel Islands Marine Sanctuary, near Santa Barbara, Calif. The work would have included marine monitoring activities, hiking and kayaking to several of the study areas.
National Geographic Alliance coordinators selected the students and teachers participating in the program.
Mr. Debeuneure was a fifth-grade teacher at Ketcham Elementary School in southeast Washington. He taught for about 20 years, said his son Jacques, 32.
A native of Whitesville, N.C., Mr. Debeuneure graduated from Johnson C. Smith College in Charlotte, N.C., with a degree in psychology and education. A father of three, he had lived in Upper Marlboro for about 17 years.
-- Michael Scarcella
The Dulles-L.A. route was new to her, and she was trying to switch back to the Dulles-Miami route.
She was 52 and married to Thomas P. Heidenberger, a pilot for US Airways. They lived in Chevy Chase and have two children, a 14-year-old son and a 20-year-old daughter who attends in Baltimore.
"She was very vibrant, a friend to everyone, very unselfish about everything" said neighbor Peter Dove.
Mrs. Heidenberger was very involved in community service, such as delivering groceries to the elderly, and was also a tennis player.
"For every one of us, at some point of our lives when we needed help, she was always the one there for us," said her sister-in-law, Betsy Heidenberger.
Michele Heidenberger was trained in how to deal with a hijacking five years ago, her sister-in-law said. "Knowing Michele, she was probably the one who would have approached them first and said, 'You can't go into the cockpit.' We have no doubt that she probably confronted these guys," Betsy Heidenberger said.
The family released a short statement yesterday, saying that Mrs. Heidenberger "died trying to protect her passengers and crew."
"We know her to have been an unselfish, caring mother, wife, sister, daughter and friend. She died a hero, putting her passengers and crew first. We know if she were with us today, she would join with family and friends in extending deepest condolences and sympathy to all who have suffered a loss in this tragic event. We know everyone will miss her too much for words."
-- Jon Morgan. The Associated Press contributed to this report.
Mr. Reuben of Potomac worked out of the Washington office of Venable, Baetjer & Howard and was blessed with a keen mind for complex taxation, real estate and business law.
"He was one of the most dynamic younger partners in our business transactions area," said James L. Shea, managing partner of the 420-lawyer firm, which also has offices in Baltimore.
Mr. Reuben came to Venable through its acquisition of a Washington-based firm two years ago. A 1983 graduate of Emory University, he earned his law degree from George Washington University in 1989.
"He was very bright and very engaging," said Mr. Shea. "He was very hard-working; ... he would work hard and deal with that stress but come out of it with a smile."
He and his wife, Vivian, had 11-year-old twin sons. Mr. Reuben was zealous about attending the boys' hockey games and taking them to watch the Washington Capitals.
"He was one of the guys who was bright and had wonderful values," Mr. Shea said.
-- Jon Morgan
He would have celebrated his 52nd birthday yesterday, said his brother, Mark W. Burlingame of Lancaster, Pa.
Mark Burlingame said his brother was in the Navy Reserve and had worked in the same area of the Pentagon where the airliner crashed. He also was organizing a 30th reunion for his Naval Academy class.
He leaves a wife, Sheri, a daughter and a grandson.
-- Lynn Anderson
Ms. Wainio, who lived in Watchung, N.J., was 27.
A 1991 graduate of Catonsville High School, she earned a bachelor's degree in communications from Towson University in 1995. She had worked in retail stores during college and had developed a great interest in what it took to make a store successful, said her stepmother, Esther Heymann of Catonsville.
Ms. Wainio, who helped oversee the 1999 opening of the Discovery Channel Store at in Baltimore, truly had a deep joy of living -- "joie de vivre," her stepmother said.
"She was just one of the most enthusiastic people," Ms. Heymann said. "She treasured and cherished her friends."
Besides her stepmother, Ms. Wainio is survived by her father, Ben Wainio of Catonsville, and her mother, Mary White of Port St. Lucie, Fla., a brother and a sister.
On Sunday, Ms. Wainio had returned from a two-week trip to Europe, where she had attended the wedding of longtime friends in Florence, Italy, and visited another friend in Paris. Ms. Wainio had told Ms. Heymann the trip was fabulous.
"She said, 'After Paris, what else could there be?'"
-- Gail Gibson