CNN reports A runway lighting issue at London's Heathrow Airport has caused delays to a number of early morning flights, the airport said in a statement Wednesday. Airline passengers in the United States and other international airports around the world took to social media to complain of being unable to take off due to delays in the UK. A statement read: "We are working to resolve the issue as quickly as possible, but at this stage we anticipate that there will be some disruption at the airport throughout this morning."