Updated: 10:30 p.m.

CLEVELAND, Ohio — Flights resumed late this evening after a power outage at ticket counters forced airlines at Cleveland Hopkins International Airport, including Continental, to cancel most of their flights today.

An airport spokeswoman said a limited number of Continental planes took off after 6 p.m.

Although electrical service was restored about 2:30 p.m., United, American, Southwest, Delta and US Air, had already scratched all flights.

Trying to ramp up again after an outage is difficult, spokeswoman Julie King said. "It's a very slow process, and there is still power down in some areas of operation," she said.

Even with power restored it was expected to take airlines a while to restore operations. Airport spokeswoman Jackie Mayo said passengers should check with airlines before returning to the airport. Anyone with flights scheduled for Monday morning should plan to arrive early since the airport was expected to be especially busy, she said.

King said customers were allowed to change schedules without penalty.

American Airlines spokeswoman Andrea Huguely said the airline canceled 16 American Eagle flights, both inbound and outbound, as a result of the power outage. American Airlines itself does not fly into Cleveland.

United Airlines canceled two flights.

The problem will affect thousands of people. Hopkins is one of Continental's hubs, with an average of 175 flights a day.

The airport has some backup power systems, but the individual airlines are responsible for having backup systems at their ticket counters. Most, like Continental, do not.

In addition to the ticket counters, the power problems were also affecting the baggage carousels and extendable boarding rampways. It also cut power to the Greater Cleveland Regional Transit Authority's airport station for its airport rapid trains.

The problem began about 6 a.m., when the power surged at a transformer on Brookpark Road in Brook Park. About 45 minutes later, power went out at the airport, Hopkins spokeswoman Jackie Mayo said.

A fire burned the transformer and the pole. No one was injured.

Road salt dust that got into the transformer may have caused the problem, First Energy spokesman Mark Durbin said.

"The fire caused the top of the pole to topple over causing the outage," he said. "All of the equipment that was on top of the pole is being replaced."

Air traffic controllers are using a back-up power system. And much of the airport has power, including the main security checkpoint, but most ticket counters remain blacked out.

Just two Continental planes will depart today before 6 p.m. Their destinations are Las Vegas and Houston, departing at 12:30 and 1 p.m.

RTA's was using shuttle buses to get riders into Hopkins, having the switch from the Red Line trains at the Brook Park station.

Charley Howard, of Youngstown, was dropped off at Hopkins at 6 a.m. to fly to San Juan, Puerto Rico, for her employer. She learned her flight was canceled at 10 a.m. and was headng back home at 11:40 a.m.

"This screws up my whole week," she said.

Videographer Gary Saunder, 32, of New York City was heading home this morning. He was told he'd have to wait until tomorrow.

Reach Continental Airlines at 800-784-4444 or Continental.com.

Plain Dealer reporter Mark Puente contributed to this story.