Interesting animation...kind of goes along with one of the theories of Cap. Cooper of the Anderson.
https://www.youtube.com/watch?v=uv4n-03mdXg
That was a pretty good video. It also shows that there was no time to launch the life boats or rafts and that the ship sank in 30 seconds or so.
With the water coming over the decks as shown in the video water could have come into the vents and flooded the cargo holds. Given that the ship was fully loaded with iron ore the cargo and the water could have sunk the ship quickly.