I was exploring a clear building with my two sons and it was not finished snd my younger son fell to his death. I just missed catching him.
Dreams about falling can often symbolize a sense of loss of control or insecurity in some area of life. The fact that your younger son falls and you miss catching him may represent a fear of not being able to protect him from harm or failing as a parent. The fact that the building is unfinished may suggest that there are still uncertainties or unresolved issues in your life that you need to address.
Overall, this dream may be reflecting your anxieties and worries about being a responsible and caring parent, and may be a message to take steps to address any concerns or insecurities you may have.