Over the holiday weekend, tens of thousand of travelers planning to hop their way around Europe were met with some unplanned delays after a systems outage caused British Airways’ operations to come to a screeching halt. Turns out the hundreds of canceled flights were the result of someone simply inadvertently switching off a power supply. 

Yes, it’s apparently that easy, you can take down an entire airline by hitting the proverbial “off” switch, The Times reports.

The airline’s investigation first centered on whether or not the data centers’ power supply unit was working correctly. Ultimately, the airline concluded that there wasn’t anything wrong with the power supply, other than a human had turned it off.

The Guardian reports the contracting firm in charge of managing the British Airways data center disagrees with the findings, maintaining that human error was not the underlying issue during the outage.

CBRE tells The Guardian that the new findings are “not founded in fact,” noting that while it supports the airline’s investigation, no determinations have been made yet.

British Airways woes began on May 27, when a power surge apparently led to a “catastrophic” systems failure that affected BA’s primary and backup systems.

In a video statement posted Saturday, British Airways CEO Alex Cruz said the airline was experiencing a “major IT system failure” that caused “very severe disruption” to the airline’s operations worldwide.

All check-in and operations systems were affected, and the airline cancelled all flights from London’s Heathrow and Gatwick airports on May 27. Worse: all of the call centers were also affected by the IT problem, and so tens of thousands of confused and frustrated customers couldn’t get flight statuses or rebook their cancelled flights.

Want more consumer news? Visit our parent organization, Consumer Reports, for the latest on scams, recalls, and other consumer issues.