my tree cant delete its children

[thebinaryblob]

I was making a tree, but when I ran it, it would not delete its children (I started out by trying to make it able to correctly delete its children)
I made a small program that demonstrates this, when I run it, it does not crash, despite the extra delete of the third node

#include <iostream>

/////////////////////////////////////////////////////////

class Node {
Node* child;

public:
Node(Node* setChild = NULL);
~Node();
};

Node::Node(Node* setChild) {
child = setChild;
}

Node::~Node() {
if(child != NULL) {delete child;}
}

///////////////////////////////////////////////////////

int main() {
Node *first, *second, *third;

third = new Node();
second= new Node(third);
first = new Node(second);

delete first;
delete third; //this should crash it

return 0;
}