TOXIC mould has been discovered in the former New York HQ of Deutsche Bank and one side of the Pentagon.
Both buildings were destroyed in the September 11 attacks.
The Deutsche Bank building, a 40-storey skyscraper on the edge of Ground Zero, became infected by mould after it was evacuated and deluged with water by firefighters.
At the Pentagon, a 37,000 sq m demolished area that is set to be rebuilt has suffered from similar effects. A spokesman for Amec, which has been carrying out the work, said: 'We supervised the remediation of mould that had grown all over many of the walls.
'We were able to minimise the amount of wall board that had to be removed by employing large dehumidifiers to dry the air.'
Mould can occur when an excessively wet structure does not dry out properly.
It has become an increasing problem in the US as flooding and storms have caused several buildings to become unusable.