Investigators quickly determined Shell was no threat. By late afternoon, they had detained Shell's ex-girlfriend and a man for questioning, according to two law enforcement sources. At least one could be charged as early as Friday, a federal source said.
Authorities were withholding their names and the possible reason behind the "pretty nasty prank," as Chief Inspector Joe Sullivan, commander of the Philadelphia Police Department's antiterrorism unit, described it.
"It's just an incredibly foolish and irresponsible thing to do," Sullivan told reporters at an airport briefing, citing the time, money, and efforts of the airline, passengers, and law enforcement officials. "The bottom line is: It's criminal."
Richard Quinn, assistant special agent in charge for national security at the FBI's Philadelphia office, said the caller could face federal charges for interfering with civil aviation.
For Snell, the day only got worse: Shortly after 7 p.m. Philadelphia time, he was arrested by Dallas/Fort Worth International Airport police for outstanding warrants from area law enforcement agencies, said David Magaña, an airport spokesman.
The airplane incident started with a 7:30 a.m. call to the Philadelphia police unit at the airport, Sullivan said. The caller said a passenger - later identified as Shell - was attempting to smuggle an explosive on a flight to Texas.
Officials immediately searched flight manifests and found the passenger listed on US Airways Flight 1267, which had left Philadelphia for Dallas-Fort Worth about 7:40 a.m.
A little more than an hour later, the plane was back, taxiing to a remote piece of runway at the Philadelphia International Airport. Shell was led from the plane and into a waiting car, but not before someone snapped his blurry photo from afar and posted it online.
For Shell, who works for a Fort Worth-based sales company, that was the beginning of a notorious day in the limelight, fueled in part by social media.
After his name first emerged as the passenger who was removed, news outlets seized on his Facebook photos and the note he posted Thursday morning before he boarded.
"I feel Blessed on[sic] of my new neighbors works Security at PHL airport, walked me right in str8 though security with a breeze," it read.
His name soon rippled across the Internet and Twitter. Then his Facebook page filled up with quips from friends.
"Not a good start to your birthday huh?!" one wrote.
Shell confirmed to the Associated Press that he was the passenger removed, but did not respond to Inquirer messages left on his cellphone and e-mail.
"If u have questions or want an interview with me, it will cost u $$$$ until then," said one of his later Facebook posts.
Flight 1267 ultimately departed for Dallas-Fort Worth at 11:14 a.m. and landed, uneventfully, three hours later. The flight had about 60 passengers, nine fewer than had first boarded.
US Airways spokesman Todd Lehmacher said several passengers may have taken other flights or decided not to fly at all.
Contact staff writer Peter Mucha at 215-854-4342 or firstname.lastname@example.org.
Inquirer staff writers Linda Loyd, Robert Moran, and Allison Steele contributed to this article.