1.   The Russian government at first said the accident occurred on Sunday, but U.S. officials have said U.S. Navy submarines detected the sound of an explosion on Saturday.

2.   On Saturday, search commanders said a Canadian submarine had detected signals coming from one of the recorders.

3.   Search commanders said Saturday that a Canadian submarine had detected signals coming from one of the recorders.

4.   Search commanders said a Canadian submarine had detected signals coming from one of the recorders.

5.   A Russian submarine detected the US vessel and Russian submarines escorted it out of Russian waters.