It does... however, there are several ways it can happen, and the path to that point is as interesting as the way it happens. Also, before letting the fact that TNO dies get you down, remember that death can be a blessing for someone who lives too long...

thank you for your answer!
It's not the fact that TNO dies that gets me down, but the fact that i know the only ending of the game.

The things that lead up to the actual death and how you accomplish it are what's really important.

There are more endings than just his death, however, they occur before you explore all locations. Yes, you can actually get a genuine ending without really finishing the main storyline.

And a second thing: The ending of 'main' quest will always be the same. There's really a higher meaning behind that, and exploring that meaning and your interpretation are what counts. Also, there are numerous characters that travel with you, and the ending of each and every one of them is affected by your decisions. Besides, in the end, you WILL want TNO to die. You'll understand that as the story continues :-)

Wouldn't worry about it. The circumstances behind how TNO dies make the story. I guess there's a parallel from, say, another story: Babylon 5...

(Off-Topic)
In the 1st episodes, Londo Mollari reveals his knowledge of his death, a trait common with his species. Londo speaks of seeing G'Kar in person for the first time, and realizing that this is the man who will kill him, hands locked around each others' throats. So the audience is aware that Londo at least believes he'll die violently in this fashion. But the story's impact comes from how the sequence of events leads to this death.
(/Off-Topic)

In the case of PS:T, you'll be exploring those events on your own. I wouldn't worry that you happen to know the ending of the game. The game is still every bit worth playing, believe us all :)

Thank you, I understand what you mean.!