The US Navy ordered a broad investigation today into the performance and readiness of the Pacific-based 7th Fleet as vessels from several nations searched Southeast Asian waters for 10 US sailors missing after an early morning collision between the USS John S McCain and an oil tanker.<br/>'<br/>It was the second major collision in the last two months involving the Navy's 7th Fleet. Seven sailors died in June when the USS Fitzgerald and a container ship collided in waters off Japan.<br/>' <br/>Defense Secretary Jim Mattis said,Navy Adm. John Richardson, the chief of naval operations, will call for a pause in operations and seek a deeper look at how the Navy trains and certifies its forces that are operating around Japan. Mattis was speaking to reporters in Amman, Jordan, where he is traveling.<br/>'<br/>''''''<br/>