User blog comment:JackfieldsA113/Can Loyal Squad Members Die?/@comment-193.190.253.147-20110116170035

Mordin is one of the squadmembers who dies fairly easy in the last mission if you put him on defense duty when you go fight the final boss. The easiest way to prevent Mordin from dying is by sending him away with the people you manage to safe or by taking him with you as a squadmate in the last fight of the mission.