Why was the Romanov family executed?

[NuclearEnergy]

I am at a loss with what occurred during the Russian Revolution. Part of me thinks it was good a monarchy was overthrown, but at the same time something just as bad or even worse followed it. However, I recently learned tonight while watching a documentary on the Russian Revolution that the Romanov family was brought into a room at midnight at executed by multiple gunmen. Even their children!!! 

I never knew this. And yes, you cannot ignore history. But when I saw this in the documentary it literally broke my heart. 

I do understand that Lenin's older brother was executed by this regime, but damn. This was a tough pill to swallow.