BOSTON – At the last minute Saturday, Lewis Katz, a philanthropist and co-owner of the Philadelphia Inquirer, invited Anne Leeds, a longtime friend and neighbor from Longport, N.J., to accompany him and two others on a quick day trip to Concord, Mass. They were going to help support a nonprofit education effort.

The day before, Katz also had invited former Pennsylvania Gov. Ed Rendell. Such spur-of-the-moment invitations from Katz were common, a function of his access to a jet and his spontaneous personality. While Rendell could not make the trip, Leeds could, and she was ready to go within a couple of hours.

But on the way home Saturday night, the trip ended in disaster when the plane exploded in a fireball in suburban Boston. Everyone on board — four passengers, two pilots and one cabin attendant — was killed.

The flight crew that died in the fiery crash had flown for the millionaire businessman for a decade, and among them was a pilot who survived an earlier fatal crash, relatives said Monday.

Katz's jet crashed during takeoff. The chief pilot was James McDowell, of Georgetown, Del. Spouses identified two of the crew members Monday as flight attendant Teresa Benhoff, 48, of Easton, Md., and co-pilot Bauke "Mike" de Vries, 45, of Marlton, N. J.

"I knew he was on a safe plane. I knew it was a well-maintained plane," said De Vries' wife, Shelly. "I know the other captain had a great, long history, [and] was also a mechanic."

The other victims were Marcella Dalsey, the director of Katz's son's foundation; and Susan Asbell, 67, wife of a former New Jersey county prosecutor.

The passengers were longtime friends of Katz, sharing his passion for trying to bolster education opportunities, particularly for children in need, and were enmeshed in the civic life of South Jersey. Katz had invited them to a fundraiser at the Concord, Mass., home of historian Doris Kearns Goodwin and her husband, Richard Goodwin, an adviser to Presidents Kennedy and Johnson.

The event, attended by 200 people, was in support of the Concord River Institute, founded by Michael Goodwin, one of the Goodwins' sons, who is a high school history teacher.

Katz often would take spur-of-the-moment trips, and his crew was at the ready. Benhoff said his wife was on call all day, every day, and they spoke throughout the day Saturday. "She loved to fly," he said. "She trusted that airplane."

Black boxes

Emergency workers at the scene on Monday found the airplane's two black-box recorders, Peter Knudson, a spokesman at the NTSB, said.

General Dynamics' Gulfstream IV, among a handful of models competing for the higher-end private jet market, had only three fatal incidents before the latest crash, according to Robert Breiling, a consultant who tracks safety in the corporate fleet.

Its accident rate, including fatal and less serious crashes, is 1.7 per million flight hours from 2009 through 2013, or less than half the total rate for all corporate aircraft.

In 911 calls released Monday, neighbors described a loud explosion and towering column of smoke. One caller Saturday night said it looked like "an atomic bomb went off" and described "a mushroom cloud" of smoke and fire.

"It sounded as if you were standing next to a cannon or close to fireworks," said Mike Stevens, 42, who was visiting family in the area.

Katz, 72, made his fortune investing in parking lots, billboards and the New York Yankees' cable network. He once owned the NBA's New Jersey Nets and the NHL's New Jersey Devils and in 2012 became a minority investor in the Inquirer.

Less than a week before the crash, Katz and Harold H.F. "Gerry" Lenfest struck a deal to gain full control of the Inquirer as well as the Philadelphia Daily News and Philly.com by buying out their co-owners for $88 million.

A public memorial service for him was planned for Wednesday at Temple University in Philadelphia, where Katz was an alumnus and trustee.