The calls came out of the sky - a reminder of the caller's love, a warning they may never return. And then silence.
Sobbing, flight attendant Ms CeeCee Lyles called her husband at home in Fort Myers, Florida, on her mobile phone, said her aunt, Ms Mareya Schneider.
"She called him and let him know how much she loved him and the boys," Ms Schneider said. People screamed in the background, Ms Lyles said "we've been hijacked" and the phone went dead, Schneider said. The plane she was on crashed south of Pittsburgh.
Moments before the San Francisco-bound plane went down, businessman Mr Thomas Burnett of San Ramon, California, called his wife, telling her he feared the flight was doomed but he and two other passengers planned to do something about it, the family's priest said.
Mr Burnett, 38, was a father of three and chief executive of Thoratec Corp, a California, medical devices company. In the call, he told his wife that one passenger already had been stabbed to death.
Father Frank Colacicco, of St. Isidore's Catholic Church, said Mr Burnett's wife, Deena, told him Mr Burnett said: "I know we're all going to die - there's three of us who are going to do something about it." Then, the priest said, Mr Burnett told his wife, "I love you, honey," and the call ended.
Authorities have not said whether an attempt by passengers to thwart the hijacking may have caused the plane to crash in the Pennsylvania countryside instead of hitting a high-profile target elsewhere.
The phone rang also at Ms Alice Hoglan's home just before dawn in San Francisco on Tuesday morning. It was her son, Mr Mark Bingham, on that same United Airlines jet.
"Hi, Mom. ... I love you very much," he told her. "I'm calling you from the plane. We've been taken over. There are three men that say they have a bomb."
Others called from jets that crashed into the Pentagon and the World Trade Centre.
Ms Barbara Olson, a conservative TV commentator and the wife of US Solicitor General Mr Theodore Olson, twice called her husband and described details of the hijacking, including that the attackers used knifelike instruments, law enforcement officials said. They gave no other details.
"She called from the plane while it was being hijacked. I wish it wasn't so but it is," her husband said. The jet she was on struck the Pentagon.
The brief morning call was a slight bit of solace for a Connecticut mother, whose adult son called minutes before his jet struck in New York City. Mr Peter Hanson was travelling with his wife and two-year-old daughter.
"All I want to say is they went down together," said Mr Hanson's mother, Eunice. "They went down together. They stayed together in death. That's the only consolation I have."
AP