LOS ANGELES (KABC) -- British Airways cancelled all flights from Heathrow and Gatwick airports as a result of a computer systems crash during a busy holiday weekend for the United Kingdom, leaving hundreds stranded at LAX.
Earlier Saturday, some travelers who flew out of London's Heathrow Airport on a flight from the airline arrived at LAX Saturday afternoon, relieved that their plane took off before the IT problems began.
"The flight was delayed initially and then we got on the plane and investigators told us there was an IT issue, I think and that was about all the detail we got. Then eventually they had some manual workaround that took a while, but we managed to eventually get out," Chris Carter said.
The airline operates hundreds of flights out of the two airports on a typical day. As the airlines website failed, long lines formed at the check-in counters and passengers expressed frustration at the airports. The outage has caused a ripple effect around the world.
American Airlines, which operates code-share flights with the airline, said it was unaffected.
The problems for British Airways come on a bank holiday weekend when tens of thousands of British families travel. Those who made it to LAX said it could have turned into a vacation nightmare.
"We've got two weeks touring around California before we head back again," Laura Carter said.
She added that the delays would have been a bad start to their holiday, especially since this is their first time in the United States.
As the evening progressed, lines formed at the airline counters as hundreds of passengers ended up stranded. Many of them expected to board an evening flight to Heathrow Airport, but found out their flights were cancelled.
"We knew there was problems in London, but the internet was showing that it was still OK to book it," traveler Sandra Hewitt said. "We booked it, got here and joined a massive queue - chaotic - and as you can see, we're still queueing."
Some said they were given confusing information by the airline. Many of those stranded travelers are now scrambling to find a place to stay for the night.
Airlines depend on huge, overlapping and complex IT systems to do just about everything, from operating flights to handling ticketing, boarding, websites and mobile-phone apps.
Officials said they believe it was a power supply issue and do not believe it was a cyberattack. They hope to have services back to normal at both London airports by Sunday, but disruptions will still be expected.
The Associated Press contributed to this report.