Once he had determined Deciding from his captives the state of defences in Manila , that the treasure ship had been unloaded at Cavite and that the Spanish squadron was undergoing Process_start extensive repairs and thus unavailable for operations , he sent Sending a raiding party against a squadron of gunboats in the mouth of the Pasig River .

On October 18 , the hurricane began Process_start undergoing rapid deepening Cause_change_of_strength and , on the next day , reached an estimated peak intensity of 165 mph ( 270 km/h ) .