I reckon the homeless man's dog 'Kiki' would've been pretty sad having lost his human. The scene ended with Kiki still barking at the water & isn't seen again, but I was left feeling pretty sad for the dog (though happy he was unharmed!)
Not any main characters. Police are shown providing supplies to a group of homeless men (they all have a great relationship). One of these guys is killed by the shark (off-screen).
MC opening scene is dragged to the depths (causing eardrum ruptures & other untold internal injuries) by the shark before freeing herself & just making it to the surface. In the catacombs slaughter scene 'Ben' is seen getting knocked out by others desperate to get out of the water, so I assume she either ended up shark chum (though that wasn't shown) or drowned. Also in that scene, a women is knocked over by others in the narrow exit & shown being trampled over underwater in the panic.