Hong Kong aviation investigators say an engine problem that caused Cathay Pacific to ground its entire fleet of Airbus A350 jets for inspection earlier this month could have escalated into “extensive damage.

A probe by Hong Kong's aviation accident investigation agency revealed Cathay Pacific's Airbus A350 engine failed in-flight due to a ruptured fuel hose which also showed signs of a fire, the agency's report stated on Thursday.

Hong Kong's air safety authority said Thursday that a defect in an engine component of a Cathay Pacific Airways Airbus A350 that caused a fire, forcing a Zurich-bound flight to return to Hong Kong, could have caused ''extensive damage'' to the aircraft.