Navy Secretary Richard V. Spencer is set to testify Tuesday before a Senate committee on two deadly ship collisions in the Pacific.

The appearance by Spencer and the Navy’s top uniformed officer, Adm. John Richardson, before the Senate Armed Services Committee at 9:30 a.m. comes after service officials testified in the House last week, saying there was no excuse for the collisions of the USS John S. McCain and USS Fitzgerald destroyers that killed 17 sailors total.