On ‘Frantic Friday’ today, Britain’s main summer vacation descended into turmoil as trains were canceled, a key road was stopped, and an airport terminal was evacuated.

After the summer break, many families were on the move, although there was some difficulty for those going to the airports at London Heathrow, Gatwick, and Stansted.

During the investigation of a fire alarm that prompted long lines at passport control, a section of Heathrow Terminal 3 was cleared this morning.

For safety concerns, workers temporarily evacuated the area after the notice, which was issued shortly after 11 a.m. Some travelers complained that this resulted in two-hour lines.

Christina Warren, who had just arrived on a Virgin Atlantic flight, tweeted, “Landed at Heathrow an hour early but there was a fire alarm so the line for passport control is literally backed up literally the entire terminal because of a fire alarm going off.”

Natalie Berg, another passenger waiting at Heathrow after arriving from the US, added, “Nearly two hours and line has barely moved at Heathrow. Just been told immigration and baggage reclaim has now reopened so hopefully on the move soon.”

And a further traveller wrote, “Fire crews investigating incident in baggage hall at Heathrow T3 mean security border is currently closed. Very long queue already.”