Heavy delays at Pearson International Airport continued Monday afternoon for passengers waiting to travel on Delta Airlines.

Only 28 per cent of Delta’s scheduled flights were off the ground by mid-afternoon as thousands of others continued to wait.

The delays stemmed from a power outage in Atlanta around 2:30 a.m. that impacted Delta computer systems and operations worldwide, the airline said in a news release Monday morning.

At the height of the outage about 450 flights at Pearson International Airport were cancelled and thousands more were delayed. Systems are improving and some flights are resuming, Delta officials said, but “delays and cancellations continue.”

As of late Monday morning, only 800 of the 6,000 scheduled flights were able to take off and some passengers said they had been waiting at Pearson for hours.

Bill Barrott was in Toronto visiting for a wedding.

“The computers were all shut down so we couldn't get our boarding passes. We had our reservation numbers but they were of no value,” he told CTV Toronto.

Barrott and his wife have been at Pearson since 8 a.m. for a noon flight to Seattle.

“We saw the information on TV,” Barrott’s wife Joyce said. “Surmised the fact that things were not going well. They were not. Good Tim Hortons coffee. Nice people in line. And we wait.”

Their flight has been moved to later this evening.

Earlier today, one couple was trying to get on a flight to San Francisco to get married.

“We're going to get married at 3 p.m in San Francisco today. We were supposed to fly out yesterday from being in Spain for a week,” Alaina Whitaker told CTV Toronto, “and then that flight got cancelled and so then they put us on this flight this morning and now here we are.”

Another man was trying to get home after a vacation in Georgian Bay.

“We're headed back to South Carolina through Atlanta and we've been sitting in this spot for three and a half hours,” said Bill Daniel.

Lou Sartor, who had travelled to Toronto for business, told CTV Toronto he arrived at the airport at 4:50 a.m.

“We were asked to go into line and I've been here ever since,” he said. “And I think it's now 9 a.m. or just shortly after nine.”

Delta has released little information to travellers -- and aside from getting to their destination, travellers said that was their biggest concern.

“They can't help what happened to me and I understand that, but they could have made announcements early,” said Jennifer O’Mara, who was travelling to Bermuda. “They could of offered us tea or coffee or water before nine o'clock this morning for the people who came early. So it's a bit annoying. I'm travelling all the way to Bermuda and I think it's just annoying.”

With files from Scott Lightfoot