These ship designs such as the Carnaval Triumph are inherent design death traps, another 'triumph' of profit/low cost over safety much like the American and Soviet designed nuclear power stations which have gone bang in recent years.

The main problem is low drafts, stacked hotel cabins, which raise the Center of Gravity and when combined with the center of Buoyancy results in poor stability due to a smaller metacentric height leading to very low angles of list before the whole structure capsizes with a very high roll speed making evacuation times very small. Augmented stability control systems using electric power (which have in this case failed) when combined with poor weather i.e wind shear and heavy seas could be catastrophic.

A ship of this size capsizing in less than a few minutes would result in thousands of casualties.

Probably not a question of if but when considering the numbers of these type of vessels especially as these ships begin to reach the end of their service life times and the pressure to have lower operating and maintenance costs in difficult economic times.