These don't look small. We will find out eventually what it got hit with but even if hit by a unmanned sub, smart move by China, will make Americans know they can't just openly roam around displaying their might.
Dude the USS Connecticut is like 9,000 ton boat. An incident with U.S. submarine and a Japanese civilian boat which the sub hit it and sank it with negligence was a 1,000 ton ship. The sub hardly felt a thing.