accept what I cannot change

there are some things that have happened to me that i would want to change , maybe people dying, the pain that that has given in my life has also helped me develop a sense of maturity. like another step on my ladder that keeps me going up.
Sometimes i can’t accept things that have happened to other people , and im thinking how can you let this happen.Sometimes this world makes it self go blind , theres no one to help each other and the innocent lives that struggle till this day.
i understand that everything happens for a reason , but what reason is there when people suffer.