HARTFORD, Conn. -- Hundreds of passengers stuck for hours on a hot, dark plane at a Connecticut airport finally reached their destination Wednesday, piling off a bus in New Jersey and describing a scene of chaos and desperation in the cabin as temperatures and tempers rose.

Some of the about 300 passengers fell ill from the heat as the London-to-Newark Virgin Atlantic flight lingered for four hours late Tuesday and early Wednesday on the tarmac outside Hartford, and at least one had to be given oxygen, said London resident David Cooper, who was en route to a job at a summer camp.

"Everyone was beginning to get a bit crazy; a few people got fevers, they were really struggling," he said. "Basically they cracked. I guess these things do happen, and this time they happened to us."

A three-hour limit on tarmac strandings that went into effect in April doesn't apply to international flights. Transportation Secretary Ray LaHood, who recently proposed extending the limit to those flights, said federal officials would investigate whether any rules were violated.

Storms diverted the Newark-bound plane to Bradley International Airport, though some passengers said they weren't told where the plane was heading or why. The plane sat on the tarmac in Connecticut from around 8:20 p.m. to 1 a.m., passengers said, as the temperature inside the plane rose and darkness permeated the cabin. Travelers said they were offered water but no food.

"After a while people panicked; people started shouting, getting more abusive," Luke McNorton said as he left one of the buses that shuttled passengers to Newark. "It got a little scary at times, you thought people might get violent."

Ken Cast, an airport operations specialist at Bradley, said a few passengers weren't feeling well and were treated by paramedics. Details weren't immediately available.

New Jersey resident Russell Homasi, returning from visiting friends in London, said that as the plane sat in Connecticut, passengers were told it had been refueled, then were told there was a problem and it couldn't leave.

Virgin was checking into reports of mechanical issues and the jet not having the air conditioner running while it was stalled.

When passengers were finally allowed off the plane and into the terminal, they said, they were delayed three or four additional hours as they waited to get through customs.

The airline issued a statement Wednesday thanking passengers for their patience and apologizing for any inconvenience.

Bradley's only regular international passenger flights are to Canada, and Virgin spokeswoman Janine Doy said the airport had to call customs and immigration officials back to the airport Tuesday night to process the passengers. The airline was forced to keep people on the plane, she said.

"It was a situation that was beyond our control," Doy said.

The plane had water fountains aboard, Doy said, but she wasn't sure whether any food was left over from the in-flight meals. Passenger Nicholas Van Pittman said water, but no food, was offered as passengers were stranded.

Kimberley Vince was heading for a job as a camp counselor on New York's Long Island and was among the several busloads of passengers arriving Wednesday morning at Newark Liberty International Airport.

The crew had made frequent announcements from the tarmac that led passengers to believe they'd be departing soon, she said.

"It was like every five or 10 minutes for four hours," she said.

Temperatures at Bradley at the time were in the mid-60s to low-70s with uncomfortable humidity, said Charlie Foley, a National Weather Service meteorologist.

LaHood this month proposed extending to foreign carriers the requirement for contingency plans in the event of a tarmac stranding. The proposal included a request for comment from airlines and the public on whether the Transportation Department should also extend a firm three-hour limit to international flights by U.S. and foreign carriers.

"The events reported overnight in Connecticut reinforce my belief that passengers have rights and are entitled to fair treatment when they fly," LaHood said in his statement Wednesday. "Our aviation enforcement office will be looking into the incident to determine whether any violations occurred."

Cast told The Associated Press that because Virgin is not one of Bradley's carriers, the airline had to call in personnel to handle the passengers.

"Being an international flight, it's not like you can let people wander aimlessly," Cast told the AP. "They need to be processed, and they need to be kept safe. Everyone has to clear customs."

A Bradley airport spokesman, John Wallace, said customs workers were at the airport Tuesday night within an hour of being called.

"Everyone did the best they could under the circumstances," Wallace said. "The process to do clearance when you have 300 people is going to take a while, plus their luggage."

The airline offered passengers vouchers for ground transportation and for hotels and was considering offering "some sort of credit" on tickets, said Chris Rossi, Virgin Atlantic vice president for North America.