In the United States, the Homeland Security Advisory System was a color-coded terrorism threat advisory scale created in March 2002 under the Bush administration in response to the September 11 attack
Threat level Orange at Raleigh-Durham International Airport (July 2008)
Homeland Security secured the Prudential Financial Building in Newark, New Jersey in August 2004 following the discovery of evidence of a terrorist threat to it.
The 2006 transatlantic aircraft plot was a terrorist plot to detonate liquid explosives, carried aboard airliners travelling from the United Kingdom to the United States and Canada, disguised as soft
Homeland Security Advisory System
…only to flights coming from the United Kingdom: August 10–September 14, 2006, in response to British law enforcement announcing it had disrupted a major terror plot to blow up aircraft, DHS raised the threat level for commercial flights from the United Kingdom to the United States to Severe. The alert was extended…
Police at the scene of one of the raids, on Forest Road, Walthamstow, London
London Heathrow Airport
Tents on the car park in front of terminal 4. Heathrow, 14 August. Erected to give people a place to stay while waiting for their flight to depart