you are using an array which is not initialized cin>>arr;
only initialize the 10th element which is not in the array and this causes problems with the destructor because I don't know why the delete  knows somehow that you used it and crashes
you should initialize it like that
In your main function when using cin >> arr;, you should run into an error since the array only to goes to index number 8, since it starts indexing at 0 it only goes up to 8. 9 is not part of the array's index.
EDIT: @Disch In his/her destructor he/she as a cout statement. That's the alert.