If It Was Caleb--Divergent alternative ending

Tobias' P.O.V.

  I hear a gunshot and run upstairs.  Please.  It can't be Tris.  I can't lose her.  I would be factionless without her.  I hear another.  Loud sobbing is coming from the room.  Could it be Caleb?  Or is it Tris?  Should I go in?  I don't want to know.  What if I see her body,motionless,on the ground? I don't want to see that.  My arms shove the doors open.
              I see Tris sitting next to someone.  Caleb.  My eyes wander and I see David.  He lays dead on the floor.  My heart sinks.  I don't know what would be worse,Tris dying or Caleb.  When I try to walk towards her,she swats me away.  I get it.  That's what I did when I thought that my mom died.   I slump down a few feet away.  She eventually gets up and we give him a quick funeral.  We don't know who we would invite anyway.  She runs onto the train and I follow.  When I do,I walk over to her. Bad idea.  "Get away from me." She screams.  What did I do? She can see that I'm hurt.  We sit in silence.  Did I just lose  the Tris I knew?  I hope not.
           When she goes to leave,she looks like she is deep in thought.  She doesn't try to jump.  Her feet just step forward.  She is trying to kill herself.  I run up to her.  I grab her hand and pull her back in.  I hold her and jump out with her.  We land on our feet.  She looks pissed.  "What'd you do that for?" She yells and throws her arms up.  "I couldn't lose you.  When I heard those gunshots my heart sank.   I thought I lost you." I say.  She runs into the compound.  I hear her quick footsteps.  She is much faster than I am.  There is no point in going after her,so I go see Zeke.  When I knock on the door he open right away.  I walk right in and sit on the couch.  My head rests in my hands and I start to cry.  "What's up man?  Is Tris okay?" He asks.  He is genuinely concerned.  I feel a hand on my shoulder and I look up.  "Yes and no." I tell him.
            "How?" He asks quietly.  I forgot how kind he could be.  "Caleb died.  She tried to kill herself on the way here." His eyes open wide.  "She went to her apartment." I say and shake my head.   "We need to get Christina." I say and run out.
           I bang my fist on her door.  "Is she okay?" Is the first thing she asks.  I wave my hand for her to follow.  When we get outside of her room,I hear sobbing.  "Okay.  Christina,Caleb died and Tris tried to kill herself on the way here." I say.  Her mouth hangs open and her eyes widen.  'Knock,knock,knock'.  Christina tries to open the door,but it's locked.  "Tris,please open up." Christina please,but nothing happens.