London’s Heathrow Airport in the United Kingdom reopened its Terminal 4 on Monday evening after emergency services declared the area safe, following a brief evacuation triggered by a suspected hazardous substance incident.
Specialist police units, firefighters, and ambulance crews had rushed to the terminal after reports of a possible chemical threat.
The Metropolitan Police later confirmed that “no trace of any harmful substance was found” despite initial concerns.
Around 20 people reported injuries during the incident, but none were considered life-threatening or life-changing.
One individual was taken to hospital while others were treated on-site by the London Ambulance Service.
According to the London Fire Brigade, crews from at least three nearby stations were dispatched to assess the situation after being alerted at 5:01 p.m. local time.
As a precaution, the entire Terminal 4 check-in area was cleared while firefighters carried out operations.
Heathrow officials later apologized to travelers for the disruption, stressing that passenger safety remains their highest priority.
“Emergency services have confirmed Terminal 4 is safe to reopen, and we are doing everything we can to ensure flights depart as planned,” a spokesperson said.
Terminal 4, which serves airlines including Air France, Etihad Airways, Qatar Airways, and Korean Air, has faced several disruptions in recent years.
It was shuttered for two years during the pandemic before reopening in June 2022 after refurbishments, and earlier this year Heathrow operations were thrown into chaos by a fire in a nearby power substation that forced over 1,000 flights to be canceled or diverted.