The 1-2-3 of rescue. Save yourself first, your partner second, and the victim last.
It's tragic that he died. You aren't supposed to go down more than 1/3 of your air supply so you have the same amount to get back with plus a third for emergencies. In addition, he was literally carrying extra oxygen tanks. I don't know the full story, but from what I understand, he wasn't fouled -- just ran out of air. In that case, it seems like he put the victims ahead of himself by acting recklessly and paid the price.
It's tragic that he died. You aren't supposed to go down more than 1/3 of your air supply so you have the same amount to get back with plus a third for emergencies. In addition, he was literally carrying extra oxygen tanks. I don't know the full story, but from what I understand, he wasn't fouled -- just ran out of air. In that case, it seems like he put the victims ahead of himself by acting recklessly and paid the price.