Federal officers were questioning employees of America's largest private security firm yesterday to discover why they lost sight of a passenger at San Francisco international airport whose shoes tested positive for possible explosive residue, then waited almost an hour before alerting the Federal Aviation Authority.
The Defence Secretary, Donald Rumsfeld, warned that the United States should prepare for potential surprise attacks "vastly more deadly" than the 11 September terrorist hijackings.
The security blunder in the US transport system forced the closure of the United Airlines terminal in San Francisco for three hours on Wednesday, as thousands of people were removed from the building and re-screened after a detailed security check of the area. Seven planes which took off before the alarm was raised had to be re-routed and their passengers re-screened.
Airport officials said yesterday they thought it unlikely the man was carrying explosives. But they were appalled that the security guard who checked him walked away to find his supervisor, leaving the man free to slip the shoes back on and head towards the departure gates. The airport, and the Federal Bureau of Investigation, also wanted to know why the evacuation order was not given until 55 minutes later.
The private firm is Argenbright Security, a subsidiary of Britain's Securicor Group, which has become a byword among US air travellers for professional lapses of all kinds.
Since 11 September, Argenbright has lost its contract at Logan airport in Boston because of numerous breaches of security. Eight Argenbright screeners at O'Hare airport in Chicago were suspended in November after they found two knives on a passenger but failed to detect seven others, as well as a stun gun and tear gas, in his hand luggage.
In Austin, an Argenbright employee was caught stealing $100 from a passenger's purse. In Denver, a company screener was sacked because he was too busy arguing with a colleague to stop a man who bypassed the metal detectors.
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