A holidaymaker returning to Heathrow Airport described the scene that greeted him at Terminal Three as akin to a "disaster movie".
Adam Kent, 59, from Worcestershire, landed on Saturday to find a "horrendous first impression of chaos".
He described luggage as looking like it had been dumped and had witnessed "appalling customer service".
A Heathrow spokesman apologised for delays saying there had been a fault with the airport's fuelling system.
"[There was] lost luggage everywhere, stacked between baggage belts everyone stepping over it and no-one doing anything about it," said Mr Kent, who was returning from Florida.
"Staff [were] nowhere to be seen, everyone was pretty shocked," he said.
"The left and abandoned luggage was left unsecured and could easily be stolen. No duty of care shown to passengers' possessions."
A Heathrow spokesman said the technical fault had been resolved, but departure flights on Saturday may be subjected to delays.
"We apologise for any impact this has on people's journeys."
Passengers had previously complained of queues and "total chaos" at the airport after it asked airlines to remove 30 flights from Thursday's schedule.
Airlines are also expected to announce further cancellations at the airport this week aimed at minimising disruption in the peak holiday season.
A government "amnesty" to the rules on airport slots is in place until Friday, allowing airlines to change schedules without facing a potential penalty.
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