Okay kiddo, so the Tower of Siloam was a tall building that was in a city called Jerusalem many many years ago. One day, the tower collapse and fell down, causing a lot of people to get hurt or even die. People were really sad and confused about why this happened.
Now, some people at the time thought that maybe all the people who were hurt or died were being punished for something bad they did. But Jesus, who was a really smart and kind person, said that wasn't true. He said that accidents and tragedies happen to everyone, and it doesn't mean they did anything wrong or bad.
So basically, the Tower of Siloam was a big building that fell down and hurt people, but Jesus taught us to be kind and understanding to those who suffer in tragedies like this.