The carrier said its money troubles will force it to cancel all departures after 7 p.m. Thursday. The end came less than 19 months after the airline's first takeoff.

"Things traditionally in the airline industry slow down drastically in January, so the total number of people that are going to be affected by this is much less than it would have been during the holiday season," said Rick DeLisi, a spokesman for Independence Air.

It was not immediately clear how many people had tickets, which DeLisi said the airline would continue selling through Thursday. On Monday afternoon - hours after the announcement - flights could still be purchased on its Web site.

"A lot of people have described the current economic conditions in the industry as the worst ever in history, and that's certainly proved to be the case in our situation," DeLisi said.

Thursday will be last day of work for most of the 2,700 employees, though about 180 will remain to close out the carrier's affairs.

The airline filed for bankruptcy protection in November. Parent company FLYi Inc. tried in vain to find a major investor or buyer.

"There has not been a firm offer put forward that meets the financial criteria necessary to continue operations," Kerry Skeen, Independence Air's chairman and chief executive officer, said in a statement Monday.

Last week, the carrier reportedly sent letters to its unionized pilots, flight attendants and mechanics, warning of the looming shutdown.

Passengers with roundtrip tickets are being contacted to see if they can return before the shutdown. Independence Air will ask a bankruptcy court to give refunds to those who cannot, as well as to people who booked flights for Friday and beyond. There will be no refunds for vouchers or free tickets.

Decisions on outstanding aircraft leases and gate space at dozens of airports will be determined through bankruptcy proceedings.

Independence Air's hub at Washington Dulles International Airport - about 30 miles west of Washington - was busy Monday. More than a dozen clerks were checking in streams of passengers.

"We knew there was a possibility this would happen, but I'll just hope it works out for the best," said a ticket agent who did not want to be identified.

"We've flown them quite a bit. They had a lot of flight options and good prices," said Chris Turpin, 37, of Indian Rocks Beach, Fla., who also gave high marks to the friendly staff.

"I've never been made angry by this airline," said Adrian Burns, 25, as he waited to check in for a flight to Columbus, Ohio.

At Dulles, Independence Air vied with discount carriers JetBlue Airways Corp., AirTran Holdings Inc. and UAL Corp.'s Ted. It also faced major competition from Southwest Airlines Co., which flies out of Baltimore-Washington International Thurgood Marshall Airport.

The company was formerly known as Atlantic Coast Airlines. It operated as a contract carrier for United Airlines and Delta Air Lines Inc., but when United sought to renegotiate its contract with Atlantic Coast at lower rates, Atlantic Coast executives decided they had a better future as an independent carrier.

After a year of planning, flights began with great fanfare at Dulles on June 16, 2004. A water cannon salute greeted the first outbound plane on what was then a schedule of 39 departures. The first flight, to Atlanta, was full.

Independence Air expanded to fly to most states on the East Coast and major cities on the West Coast. In recent months, it was forced to drop several routes.