Why did arrestee die in Minsk pre-trial prison’s hospital?

As part of the monitoring of the penitentiary system carried out by the Human Rights Center "Viasna", human rights defenders keep receiving letters in which prison inmates provide specific evidence of human rights violations against people in custody and serving sentences, including allegations of torture, and other evidence of inhumane treatment to prisoners.
In one of the recent letters a prisoner who is now serving his sentence in a penal colony reports evidence of the tragic events that took place in the afternoon of June 11, 2010 in the pre-trial prison in Valadarski Street in Minsk.
The following events took place in cell No. 30 located in the prison hospital for defendants and arrestees who are suspected of having tuberculosis. Opposite it is cell No. 27 for patients with mental disorders. Both cells are equipped with ventilation windows 10-20 centimeters high through which one can see part of the corridor in front of the cells.
Then the prisoner says:
"At the time I was in cell number 30. I heard loud shouts one of the patients in cell number 27, which attracted the attention of all of our inmates. Although, it should be noted, such cries can often be heard from the cell. Then there appeared a controller on duty at the hospital and medical staff. However, making sure that there was no violence used by other inmates against the patient, they requested that the patient stopped shouting and calmed down, otherwise the rest of the controllers would be called for. The duty inspector also demanded from other patients that they "influenced" the loudmouth. After that, it was quiet for a while. But at about 5 p.m. screaming resumed, and it became even more violent.
I watched the events together with other inmates through the ventilation window. Several inspectors re-entered the cell and after some minutes of fuss started "calming down" the patient with rubber truncheons. At the same time we heard loud laughter, which testified that the supervisors enjoyed battering the patient. Finally, the patient was knocked down, tied up and tied to the bed. He screamed and tried to free himself. For this he was beaten again. As a result, the patient grew silent, and the inspectors left, closing the door of the cell.
It was almost time for evening change of controllers’ shift, which takes place at 6 p.m.
After the shift change, we heard someone rattling at the door from inside of cell No. 27 and asking for prison staff to come. A controller named Nastya appeared, who was told that the patient had stopped breathing. Hearing the complaints the inspector left, and some 40 minutes later we heard persistent knocking again. The knocking was growing louder and louder. The controller reappeared, and the patients told her that their cellmate needed urgent help, because he had shown no signs of life for almost an hour. The controller called for help. Sasha (paramedic on duty) came (the name can not be real), together with the building head and several supervisors. They opened the cell and untying the patient dragged him into the hallway. There the doctor began to massage his heart. After the doctor ran to the treatment room and returned indignant that there was no adrenaline there... the building head then went to the phone and saying that he was going to call for an ambulance phoned checkpoint No. 1. He then asked the paramedic what to report. The answer was: "Tell them he has stopped breathing."
We, in our cell, heard the conversation of the controllers with the building head who named the patient as Semianovich, and one of those who an hour before beat him - Babko. Finally, the inspectors noticed that we were overhearing them and closed the ventilation window of our cell. We did not see anything else, but heard through the door that the patient was dead..."
Commenting another evidence of criminal inaction by the staff of prison No. 1 in Minsk, which resulted in the death of a prisoner, expert of the Human Rights Center "Viasna" Pavel Sapelka notes the following:
"I have known for a long time that life and health are not the highest values in prison​​. Pre-trial detention centers, which contain, as a rule, the persons who have not been found guilty of a crime are not an exception to the rule: the staff of these institutions have already passed their guilty "verdict" on the convicts... Isolated cases of abuse of prisoners have become widely known, and there were several reasons for that. First, the prison system has discouraged prisoners from reporting and providing evidence in cases where they witnessed the abuse by prison staff.
Second, the authorities entrusted with the duty to address the reported cases of this kind are rather obsessed with their clean uniform than the execution of the law.
Third, the lack of public control over places of detention allows for the concealment of what may become the object of attention of the prisoners’ relatives, lawyers and human rights defenders. Even in cases where the crime is addressed by the court, as it was after the death of one of the prisoners in the jail of Babruisk, the court’s assessment because of its softness does not match the gravity of the crime committed by the prison officials."