Possibly stating the obvious, but anyway....

1) did you check the content of "level"? What was inside this string while the crash occured?
2) log the addresses where "me" and "you" are pointing to at that stage. I assume the pointers are not NULL while pointing at some entity which has already been removed. That would explain why the array access above (2nd example) does not yet crash, because you're not accessing some NULL pointer there.