A swift, spectacular, and damaging line of storms ripped through the region at the height of the afternoon commute Tuesday, disrupting mass transit, taking down trees, and knocking out power to a half-million electric customers.

What was far and away the worst outbreak of severe storms this year forced both SEPTA and PATCO to suspend service for a time, and shut southbound lanes on a portion of the New Jersey Turnpike.

PATCO announced about 11 p.m. that service would not be restored until mid-morning Wednesday, meaning no trains would run during the morning rush hour.

Shortly before 7:30 p.m., SEPTA announced that some service had been restored on the Paoli/Thorndale and Norristown High Speed Lines.

An Amtrak train that departed Harrisburg for Philadelphia lost power in Chester County and was stranded for several hours. Passengers complained on Twitter that they had no air conditioning and no access to water. The train resumed service around 10:20 p.m.

Marie Winters, 41, of South Philadelphia, was returning from a business trip in Harrisburg when the train stopped somewhere between Parkesburg and Coatesville.

"We were stranded in the middle of nowhere for about 4 hours with no water, AC, or any idea if/when the train would move," Winters said in an e-mail.

The potent storms, with near-hurricane-force wind gusts, were spawned by a rapidly moving front that evidently focused its ferocity on Delaware and Chester Counties, parts of Philadelphia, and South Jersey.

About 500,000 customers lost power in the Philadelphia region. Atlantic City Electric reported that 249,000 of its 545,000 customers were without power in its eight-county region, which includes parts of Cape May, Atlantic, Burlington, and Gloucester Counties.

Peco reported 170,000 outages, primarily in Delaware and Chester Counties, and PSE&G, more than 86,000 in South Jersey.

Five people were injured in two building collapses in Philadelphia.

Four people were hurt when a building collapsed shortly after 6 p.m. in Fishtown, police said. Shortly after 7 p.m., a woman injured one foot in a partial collapse of a building in Feltonville. None of the injuries was life threatening, police said.

A tornado warning had been issued by the National Weather Service at one point, but no sightings had been confirmed, said Valerie Meola at the Mount Holly office.

Further examination of the storm and resulting damage could lead to a confirmation later of a tornado, her colleague Lance Franck said later.

The straight-line winds, however, were impressive. A gust of 71 m.p.h. was reported at Philadelphia International Airport - 3 m.p.h. shy of hurricane force. In addition, 70 m.p.h. gusts were recorded in Glassboro and King of Prussia.

The front bearing the storms moved through quickly, and the damage was swift. "It was booking it," Meola said.

The storms got a jolt from the sultriness of the day, with the sun's energy providing an extra kick.

Meola noted that this generally has been a quiet severe-storm season in the region, "but this is one that people will probably remember."

At the Deptford Mall in Gloucester County, the storm ripped through a parking lot near Boscov's department store, blowing out car windows and flipping a blue Honda on its roof. Broken glass lay scattered on the ground. By nightfall, security had roped off the damaged cars with yellow police tape and banned reporters from the parking lot. Anxious car owners made telephone calls as they awaited the arrival of tow trucks.

A mall spokesman could not be reached for comment.

Tyler Poole, 19, of Sicklerville, was working at the Red Robin restaurant inside the mall as a host when he learned that a coworker's car had been flipped over by the storm. Poole said he became concerned because he always parks next to that colleague.

Poole rushed outside, where he discovered that three windows on his silver 2009 Nissan Ultima had been shattered.

"I didn't hear the storm at all. I was very upset," Poole said. "I just thought: How am I going to get home?"

His parents were quickly en route to pick him up.

Most of the damage appeared to be confined to the Clements Bridge Road entrance to the mall. A tree outside Boscov's was partially uprooted and a sign near the mall entrance was tilted. A mall spokesman could not be reached for comment.

In Northeast Philadelphia, an almost-2-inch main gas line broke after it was pulled out of the ground Tuesday night by a falling tree, according to Melanie McCottry, a Philadelphia Gas Works spokeswoman.

Heavy winds downed the tree on the 4600 block of Adams Avenue around 7 p.m. McCottry said that she was not sure how long it took for workers to bring the gas leak under control, but that it was not an extended period of time.

No injuries were reported, and no homes were evacuated.

Tree damage was ubiquitous in the areas targeted by the storms. Numerous roads were closed off; trees crashed into houses, and several fires, probably sparked by lightning, were reported.

Jessica Schemelia, 32, was at home with her family in Gloucester Township, Camden County, when the sky darkened, the wind picked up, and the lights began to flicker. In light of the tornado warning, her family decided it was time to head for the basement. As she walked down, she peered out a window and saw a 60-foot-tall tree on her property crash into her neighbor's house.

"It seems to have taken out the whole left corner of the house," she said later. The tree's branches also crashed onto two cars in the neighbor's driveway. Fortunately, no one was hurt, Schemelia said.

"The power of the wind was unbelievable," she said.

Around 6 p.m., Don Garlanger, 62, was driving from a Cherry Hill pizza shop to his Maple Shade home. As he turned onto Wayne Road, he saw a flash and heard a loud cracking sound.

A giant tree smashed through the windshield of his Infiniti. Garlanger sat trapped in the car for 45 minutes.

Lou Elbert, 84, came out of his home to see Garlanger's vehicle trapped underneath the tree and live wires. Garlanger honked the horn. Elbert was preparing to cut branches in an attempt to free Garlanger when police arrived.

Two hours later, Garlanger was standing on the side of the road with a small scratch on his left leg and a concern about what to do about his car, which was still trapped.

"He has a guardian angel or two watching over him," said his niece Dawn Pizzo, 45. "He's lucky to be alive."

Debra Sellitto, spokeswoman for Gloucester County, said the county's hazmat squad was dispatched to the PBF Energy Paulsboro Refinery, in Greenwich Township, for a report of a possible lightning strike. As of 9 p.m., no damage was reported and officials gave the all-clear.

Downed wires, trees, and poles were reported throughout the county, she said, but officials were still assessing specific damage.

"I was driving and I felt like it was the end of the world - dark out and tree branches flying everywhere. I had to swerve so I wouldn't hit them," said Bob Hartman, referring to conditions in his hometown of Wenonah.

About an hour after numerous old trees were uprooted, stunned people in the Gloucester County town began walking through the streets, surveying the damage.

"It looks like the night of the walking dead," said one boy.

Passengers on SEPTA's Regional Rail lines found themselves stuck on trains as the storm wrought havoc on the transit system.

"I'm stuck on SEPTA, not moving, & they've cancelled trains to my stop. My husband tells me there's no electric at home *sigh*," Sabrina Vourvoulias tweeted from a Thorndale train that was stuck at Suburban Station in Center City.

Vourvoulias, managing editor of the Latino bilingual newspaper Al Dia, said in an interview that her 6:07 p.m. train had made it to the end of the platform and then "stalled there for about a half hour."

She was headed to her home near Downingtown, Chester County, but SEPTA employees at Suburban told her that it was unlikely that trains would resume that far Tuesday night because of power issues and a downed tree.

She checked with a Center City hotel and found out it was charging $400 for the night. But then SEPTA announced partial restoration of service, and Vourvoulias was hoping to find her way home.

bmoran@phillynews.com

215-854-5983 @RobertMoran215

Contributing to this article were Inquirer staff writers Melanie Burney, Sam Carchidi, Angelo Fichera, Rita Giordano, Erin McCarthy, and Mari A. Schaefer; Philly.com staff writer Tommy Rowan; and former Inquirer staff member Pat Mazurek.