Late on the 28th February, Stalin held a Party at his dacha with some of the leading members of the Politburo. After they left, in the early hours of 1st March, Stalin retired to his quarters, along with strict instructions that he was not to be disturbed unless there were indications that he was awake and moving about.
However, nothing was heard, a light came on at some point, but it was only the following evening, that tentatively, someone went into Stalin's rooms and found him on the floor, confused or unconscious, accounts differ, and clearly seriously ill. It was soon established that he had had a major stroke and efforts were made to try and save his life, but on 5th March, Stalin died, leaving a power vacuum and the Soviet Union having to face major changes as a result
It says something about Stalin that, in his final days, people were scared of going to see if he was alright when they had heard nothing to indicate he was okay. In the years to come, many soviets had to come to terms with what sort of person he was, and that is something some still struggle with. One of the most brutal dictators of the 20th Century still has the power to attract or repel