Cal is just dead?

I've finally got to act 2 on my own personal play through, and of course i'm trying to get as many achievements as i can so i don't have to hunt for them later. And just so everyone knows i'm playing on the easiest difficulty just to experience the story first and get the easy achievements.

The two achievements i'm going now are the long ones, Karlach dating and no tiefling left behind.

I saved everyone in act one, and just saved everyone from the shadows, the demon attack, and the prisoners in the prison. Was about to leave for the shadowfell before remembering about saving rolan from shadows. So after quickly saving him and going to the Last light in to see what cutscene or conversations they have i find out cal is dead. There was no fight, i got them through the boats, i even left with them through the boat, but now after like 3.7 hours after that whole thing i find out he is dead.

So i'm hesitating whether to go back a whole 3 hours just to make sure he lives, but i just got done all of the shar temple.

Does anyone know what happened?