Who died during your first playthrough of the suicide mission of Mass Effect 2?

[Princess Cadance]

None. Because I'm a completionist whore when it comes to video games.(I finished the mineral scanning mission in ME1 and discovered every location in Fallout 3 past the requisite for that one 360 achievement. I'm a whore.) I wouldn't have really cared if Jack died though. Most of the loyalty missions endeared me to the characters. Jack's scared me.

"Here's where I killed my first man."

"Oh my god, why am I here?"

[Jakethe_Snake15]

Grunt and Mordin. I really liked Mordin too - his singing was legitimately one of my favorite moments in this series.

[SturmChurro]

I am playing through 1-3 atm as vanguard (playing multiplayer in 3 for the readiness % right now). Mordin was the only one who died, and I don't know why. All my companions were loyal. I should have taken him with me for the boss fight. I read online it happens and doesn't happen to some people.

[Tankfriend]

Sending him back with the crew of the Normandy is usually a surefire way to have him survive.

[Sir Adrian]

Miranda. Just as planned

[Iron Aquilifer]

Miranda, And two others.... No idea why (had all loyalty/upgrades) so I restarted until everyone was alive and well

Remember thinkin one time that I had got everyone back alive and then saw one coffin..... Didn't even figure who it was

[vipercobra16]

I had Jack die because I didn't upgrade armor. Then Jacob died in the vents and Mordin died holding the line. I liked Zaeed's death because he starts out only caring about money but died a hero, protecting the crew. I personally think the story works better if a couple of people die, so I usually kill off ones I don't like or give my favorites, who aren't important in ME3, a heroic death.

[Kaiser Leonidas]

I managed to do this first time without losing anyone. I think I just got lucky in trying to pick whoever I thought was best suited to each task (Garrus for squad leader, Samara to do the biotic shield, etc.), and they all happened to be the right ones.

[Dawnbreaker]

Mordin the poor bastard ;( i still miss him... then i found out what happened and on second play through no-one died

[Crusader Vanguard]

I got through without anyone dying the first time around, because I paid attention to each companions strengths and did ALL side missions, trying to complete the game rather than just run through it almost blind.

To get everyone through alive you must 1) do all loyalty missions, 2) get all THREE upgrades for the Normandy, 3) not wait too long after the crew is taken (if I remember right, you can wait one mission before half are killed off, and that's so you can do Legion's loyalty mission), and 4) certain companions are better suited for different roles during the mission, based on character strengths.

9 Step-Guide to keep everyone alive... or how to kill everyone!

Spoiler Alert, click show to read: 

1. If the armor upgrade for the Normandy is not purchased, Jack dies.

2. If the shield upgrade for the Normandy is not purchased, one of your non-party selected companions will die in this order (first one not-party member dies): Kasumi, Legion, Tali, Thane, Garrus, Zaeed, Grunt, Samara/Morinth

3. If the weapons upgrade for the Normandy is not purchased, one of your non-party selected companions will die in this order (first one not-party member dies): Thane, Garrus, Zaeed, Grunt, Jack, Samara/Morinth

4. For the "Specialist in the Vents": Only Tali, Legion, or Kasumi (IF they are loyal) will survive, also assuming you picked a good leader for the first fireteam!

5. For the "Leader of First Fireteam": Only Miranda, Garrus, or Jacob (IF they are loyal) can successfully lead the first fireteam and get the Specialist out in time.

NOTE: If anyone else NOT listed is selected for either role in 4 or 5, the Vent Specialist will die.

6. For the "Biotic Specialist": Only Jack, Samara, or Morinth (IF they are loyal) will hold the barrier with no causalities.
If someone else is selected, ONE companion will die in this order: Thane, Jack, Garrus, Legion, Grunt, Samara, Jacob, Mordin, Tali, Kasumi, Zaeed, Morinth

7. For the "Leader of Second Fireteam": Again, only Miranda, Garrus, or Jacob can lead successfully without being killed at the end. NOTE: If I recall correctly, Miranda actually DOES NOT need to be loyal for this segment for her to survive (for the first fireteam she DOES though), however, Garrus and Jacob DO need to be LOYAL to survive leading the second fireteam.

8. Do you send a companion to escort crew back? YES! If you do not, the crew DIES. It DOES NOT MATTER which companion you send, as long as they are LOYAL. Mordin is the most popular choice for this assignment, as he seems to die at strange times. Mordin, if LOYAL, will return the crew safely, for example.

9. The two squad members to take with you into the final battle with the Reaper must be LOYAL to survive. Doesn't matter who comes with you. "Hold the line" companions will survive if they are LOYAL as well.

There you go. If you get all 3 upgrades for the Normandy, do all companion Loyalty missions, and make smart choices for Vent/Biotic Specialist and Team Leaders as listed, all companions come out alive! Have fun!