Can someone please explain to me why my getHead() getter is getting a Segmentation fault?

I feel like this should work. I can get other binary tree leafs, but this one is giving me an error. Am I somehow changing it and I don't know? I've been debugging this for hours and I can't get it to work. Thanks in advance for your help.

Everything else is working for me on this, so I'm not sure where my logic went wrong.

struct node{
    int id;
    string data;
    node* left;
    node* right;
};

class binSearchTree
{

private:
    node* head;

public: 

    binSearchTree(node* n);
    node* CreateLeaf(int);
    // change add to void   
    void add(int id, node* & nPtr);
    void inorderTraverse(node* nPtr);
    node* getEntry(int id, node* nPtr);
    int getID(node* nPtr);
    node* getHead();
    string getData(node* nPtr);
    // bool remove(int);    
};

binSearchTree::binSearchTree(node* n){
    this->head = n;

}

node* binSearchTree::CreateLeaf(int id){

    node*n = new node;
    n->data = "This has id number: ";
    n->id = id;
    n->left = NULL;
    n->right = NULL;

    // returns pointer to node
    return n;
}

void binSearchTree::add(int id, node* & nPtr){

    // if root is empty, set root to NULL
    if(nPtr == NULL){
        nPtr = CreateLeaf(id);
        cout << "Adding head " << nPtr->id << endl;
    }
    // Check if need to go left
    else if(id < nPtr->id){
        // if id is less and left not NULL, go left again
        if(nPtr->left != NULL){
            add(id, nPtr->left);
        }
        else{
            nPtr->left = CreateLeaf(id);
        }   
    } 
    // go right     
    else if(id > nPtr->id){
        if(nPtr->right != NULL){
            add(id, nPtr->right);
        }
        else{
            nPtr->right = CreateLeaf(id);
        }
    } 
    // if id has already been used print out error message
    else{
        cout << "The id " << id << " has already been used" << endl;
    }   
}

void binSearchTree::inorderTraverse(node* nPtr){

    // If the binary tree isn't empty
    if(nPtr != NULL){
        // go left 
        if(nPtr->left != NULL){
            inorderTraverse(nPtr->left);
        }
        // print out the id
        cout << "Now printing out " << nPtr->id << endl;
        // go right
        if(nPtr->right != NULL){
            inorderTraverse(nPtr->right);
        }
    } 
    // If empty output that binary tree is empty
    else{
        cout << "This binary tree is empty" << endl;
    }
}

node* binSearchTree::getEntry(int find, node* nPtr){

    //if head passed in is NULL, return NULL
    // this is the base case
    if(nPtr == NULL){
        // cout << "Nothing here" << endl;
        return NULL;
    }
    else{
        // return node if found
        if(nPtr->id == find){
            return nPtr;
        }
        // if less go left
        else if(find < nPtr->id){
            return getEntry(find, nPtr->left);
        }
        // if more go right
        else if(find > nPtr->id){
            return getEntry(find, nPtr->right);
        }
    }
}

int binSearchTree::getID(node* nPtr){
    return nPtr->id;
}

string binSearchTree::getData(node* nPtr){
    return nPtr->data;
}

node* binSearchTree::getHead(){
    return this->head;
}

int main(){

    int TreeKeys[16] = {50,76, 21, 4, 32, 64, 15, 52, 14, 100, 83, 2, 3, 70, 87, 80};

    node* head;
    head = NULL;
    binSearchTree myTree(head);

    myTree.inorderTraverse(head);

    for(int i = 0; i < 16; i++){
        myTree.add(TreeKeys[i], head);
    }

    myTree.inorderTraverse(head);

    node* temp;

    temp = myTree.getEntry(50, head);
    cout << myTree.getData(temp) << myTree.getID(temp) << endl;
    delete temp;
    temp = NULL;
    temp = myTree.getEntry(80, head);
    cout << myTree.getData(temp) << myTree.getID(temp) << endl;
    delete temp;
    temp = NULL;
    temp = myTree.getEntry(120, head);
    if(temp != NULL){
        cout << myTree.getData(temp) << myTree.getID(temp) << endl;
    }
    else{
        cout << "Not found" << endl;
    }
    delete temp;

    // Get the head
    temp = NULL;
    temp = myTree.getHead();
    cout << myTree.getData(temp) << myTree.getID(temp) << endl;

    return 0;
}