When they arrive at Buchenwald, Eli's father is growing ever weaker. Clinging to each other's hands, they try to keep moving and keep together. The rumor is making the rounds that they are to have showers then be sent to barracks. While awaiting an opportunity to join the throng trying to get into the showers, Mr. Wiesel collapses on a snowbank in weakness and exhaustion. Elie screams at his father to get up and keep trying but too much has happened to Mr.Wiesel. In delirium, he responds that Elie must allow the corpses to sleep and not awaken them with shouting.

Their personal agony is interrupted by the sound of the air raid warning. Elie runs for cover in the barracks--foregoing the crush to get into the showers--discovering in the morning that his father has not followed him into the barrack. He feels horror at himself for not insuring his father's safety. He goes looking for him. After hours of searching, he finds him and sees that Mr. Wiesel has deteriorated significantly since the scene on the corpse snowbank. This deterioration ushers in a more rapid decline. He sometimes cannot recognize Elie. Then, to add cruelty to pitiless fate, Mr. Wiesel develops dysentery.

"He is very sick."
"The doctor won't do anything for him."
He looked me straight in the eye. "The doctor cannot do anything more for him ...."

On the night of January 28th in 1945, Elie goes to his bunk in exhaustion with his father still alive and still in the bunk below him.

I had to go to sleep. I climbed into my bunk, above my father, who was still alive. The date was January 28, 1945 ....

In the morning, another inmate is in Mr. Wiesel's bunk. Mr. Wiesel had been taken in the night--whether dead or still alive--to the crematorium. Elie felt no tears, only relief "deep inside":

if I could have searched the recesses of my feeble conscience, I might have found something like: Free at last!

This is how Mr. Wiesel dies: surrounded by his son's desperation shrouded in guilt; exhausted and worn beyond endurance; suffering dysentery and the thirst of it, with no help at hand; in the night, amidst the rock-hard slumber of those near dead; perhaps in a pathetic bunk, perhaps in the crematorium.

During the death march to Gleiwitz, Elie's father, Chlomo, already weakened, grows sick and exhausted. By the time they arrive at the Buchenwald concentration camp, Chlomo has passed out in the snow. Elie has long been resentful of his father, whom he now sees as a burden. Despite his own exhaustion and resentment, Elie tries to take care of his father. He remembers the situation of Rabbi Eliahou and his son: seeing his weakened father limping, the son left him behind. Elie vows to never treat his father the same way, even though he is tempted to do so.

The morning after their arrival at Buchenwald, Elie obtains coffee for his feverish father, who drinks the hot beverage with the "gratitude of a wounded animal." He gives his father his share of the rations and tries to comfort him as best he can. Eventually, Chlomo grows too weak to even get up to relieve himself, angering the other inmates.

His death comes one night when he is crying out for Elie. Terrified of the camp guards, Elie does not move, even when his father is beaten on the head by an SS officer. By the next morning, his father's place has been filled by another prisoner. Elie feels both relief and guilt over the matter.

Night by Elie Wiesel is Elie's autobiographical story of his time in several concentration camps during Hitler's reign of terror against the Jewish people during World War II.

Before they are shipped off to the camps, Elie's father is a prominent figure in the Jewish community. He is rather careless about his family and the day-to-day lives they lived, but he is a good man. 

When things got bad enough, he had several chances to take his family away and escape the tragedy, but he did not really believe things were as bad as others seemed to realize.

When they get to the camp, Elie and his father are separated from the female members of the family, so the rest of the story is about the two of them. Elie's father is quite ill-suited to hard labor and stern taskmasters, and there are times when Elie rather wishes his father would just kind of "tough up" a bit. Despite that, he is a good father who does his best to take care of his son.

The dehumanization begins early, and there comes a time when Elie does not even respond emotionally when his father is mistreated by the guards. Instead, Elie, like all of the prisoners, really only has the physical and emotional energy to worry about his own survival.

Several times throughout the story, Elie's father narrowly escapes selection--being sent to the death chambers. His physical condition slowly deteriorates, of course, due to the living conditions in which they all live. Things rapidly get worse for the older man when the prisoners are all forced to march to a new camp in the bitter cold and snow.

Elie nearly dies when he falls asleep in the snow, but his father rouses him and saves his life. When they eventually arrive at Buchenwald, however, Elie's father has no more strength and begins to deteriorate. He is constantly feverish and suffers from dysentery (chronic diarrhea), and the guards no longer want to waste any food on a man they can see is so near death. 

At times, Elie's father does not even recognize his son and seems to be already in another place, a better place. Other prisoners beat him up when Elie is not there to protect him. His father is in unbearable pain and wants something to quench the burning on his insides. Elie cannot help.

On January 29, Eli wakes up and someone else is sleeping in his father's cot. Elie recounts it this way:

They must have taken him away before daybreak and taken him to the crematorium. Perhaps he was still breathing....

No prayers were said over his tomb.No candle lit his memory. His last word had been my name.He had called out to me and I had not answered. 

It is sad to say, but Elie's father died from the same thing so many others died from--simple neglect and constant abuse. His body just could not sustain itself given the treatment he was exposed to in the camps and, like so many others, he just quite breathing.

It is, of course, possible that he was not dead when he was taken away and actually died in a fiery furnace; however, he would have died imminently in any case. The reality in either scenario is that his body just could not sustain life any longer.