Genevieve Mercier, a nurse who passed the time with a French novel about a plane crash, arrived 3½ hours early for her flight home to suburban Montreal in anticipation of heavy security.

In Los Angeles, Kim Pinney, who operates a daycare center in Virginia, booked the latest flight home possible from a friend’s wedding in the belief that would minimize her chances of falling victim to a terrorist attack.

“If something was going to happen, it would happen during the day and then it would be over,” said Pinney, 39. Since her flight is at 11 p.m. Sunday, she added, “Technically, I’m flying for an hour on 9/11 because it will be 9/12” for most of the flight.

“I spoke to many business people who would wince when they heard I was traveling on 9/11, but I don’t want to do that,” said Patrick Bienvenue, a native of Canada who dressed in red pants and a blue-and-white checked shirt to show his affection for the United States, his home for the past three decades. The Rockport, Maine, real estate executive was flying out of Boston and headed to Miami.

Pam O’Hara, a nurse specializing in pediatric oncology whose husband is a retired New York firefighter who responded to the attacks on the World Trade Center, was returning to Hazlet, New Jersey, with her daughter, daughter-in-law and granddaughter from a nursing conference in Anaheim, California.

She said she was apprehensive enough about flying on the anniversary that she avoided any flights from the Los Angeles airport and Kennedy Airport, figuring that they would be more desirable targets for terrorists.