C++ LinkedList Queue Implementation and Destructor Error:"Aborted (Core Dumped)"

I'm trying to learn about C++ and I am having issues with memory management and the concept of destructors. I have tried to write a Queue implementation using Linked Lists, and I am receiving "Aborted (Core Dumped)" error messages when I try to delete my linked list nodes in my destructor method (bolded). If anyone knows what I'm doing wrong please let me know!

Here's the code for my destructor method:

template <class T>
Queue<T>::~Queue(){
  Node<T> *currHead = head;
  while(currHead != NULL){
    Node<T> *nextHead = currHead->next;
    delete currHead;
    currHead = nextHead;
  }
  Node<T> *currTail = tail;
  while(currTail != NULL){
    Node<T> *nextTail = currTail->next;
    delete currTail;
    currTail = nextTail;
  }
}

And for reference here's my full linkedlist queue implementation:

template <class T>
class Node{
public:
  T data;
  Node<T> *next=NULL;
};

template <class T>
class Queue{
public:
  Queue();
  ~Queue();
  void push(T);
  T pop();
  int size=0;
  Node<T> *head=NULL;
  Node<T> *tail=NULL;
};

template <class T>
Queue<T>::Queue(){}

template <class T>
Queue<T>::~Queue(){
  Node<T> *currHead = head;
  while(currHead != NULL){
    Node<T> *nextHead = currHead->next;
    delete currHead;
    currHead = nextHead;
  }
  Node<T> *currTail = tail;
  while(currTail != NULL){
    Node<T> *nextTail = currTail->next;
    delete currTail;
    currTail = nextTail;
  }
}

template <class T>
void Queue<T>::push(T data){
  Node<T> *node = new Node<T>;
  node->data = data;
  if(head == NULL){
    head = node;
  }else{
    tail->next = node;
  }
  tail = node;
  size++;
}

template <class T>
T Queue<T>::pop(){
  if(size == 0){
    throw "Empty Queue";
  }else{
    Node<T> *oldHead = head;
    T oldData = oldHead->data;
    head = head->next;
    size--;
    delete oldHead;
    return oldData;
  }
}

EDIT:

I've also tried the following definition for the destructor but I am getting the same error:

template <class T>
Queue<T>::~Queue(){

  while(head != NULL){
    Node<T> *currHead = head;
    head = head->next;
    delete currHead;
  }

  while(tail != NULL){
    Node<T> *currTail = tail;
    tail = tail->next;
    delete currTail;
  }
}