Insertion of tree nodes embedded in a list

[skuzzy]

struct t_node
{
    char word[20];
    int wordAppears;
    
    struct t_node *left;
    struct t_node *right;
};
typedef struct t_node TREE_NODE;

struct t_tree
{
    TREE_NODE *root;
};
typedef struct t_tree TREE;

struct node
{
    char title[50];
    int height, wordsInTree;
    TREE *tree;
    
    struct node *next;
};
typedef struct node LIST_NODE;

struct list
{
    LIST_NODE *head;
};
typedef struct list LIST;

TREE_NODE *addTreeNode(char *string, TREE_NODE *pCurrent)
{
    if(pCurrent == NULL) //if the root doesn't exist yet
    {
        pCurrent = (TREE_NODE *)(malloc(sizeof(TREE_NODE))); //create new node
        pCurrent->wordAppears = 0;
        pCurrent->left = NULL;
        pCurrent->right = NULL;
        strcpy(pCurrent->word, string);
    }
    else if(strcmp(string, pCurrent->word) < 0)
        //word is smaller, send left
        addTreeNode(string, pCurrent->left);
    else if(strcmp(string, pCurrent->word) > 0)
        addTreeNode(string, pCurrent->right);
    else
        //we have a match and we should increment the word counter
        pCurrent->wordAppears++;
   
   return pCurrent;
}

void loadData(FILE *file, LIST *chapters)
{
    LIST_NODE *currentChapter;
    int totalChapters = 0;
    int i = 0;
    int wordsInTree = 0;
    char word[20];
    
    fscanf(file, "%d\n", &totalChapters);
    
    currentChapter = chapters->head; //initialize outside loop
    while(i < totalChapters)
    {
        if(currentChapter == NULL) //this is the first chapter
        {
            currentChapter = (LIST_NODE *)(malloc(sizeof(LIST_NODE)));
            currentChapter->tree = NULL;
            currentChapter->wordsInTree = 0;
            currentChapter->height = 0;
        }
        //create the tree
        currentChapter->tree = (TREE *)(malloc(sizeof(TREE)));
        currentChapter->tree->root = NULL;

        //read title and the number of words in the file
        fscanf(file, "%s %d", &currentChapter->title, &currentChapter->wordsInTree);
        wordsInTree = currentChapter->wordsInTree;
        
        //currentChapter->height = heightOfTree(currentChapter->wordsInTree);
        
        //fill the tree
        while(wordsInTree > 0)
        {
            fscanf(file, "%s", &word);
            //printf("%s\n", word);
            addTreeNode(word, currentChapter->tree->root);
            wordsInTree--;
        }
        
        if(i == 0)
        	chapters->head = currentChapter; //fill head node
        
        currentChapter->next = (LIST_NODE *)(malloc(sizeof(LIST_NODE)));
        currentChapter = currentChapter->next; //move to next node
        i++;
    }
    
    //printf("%s\n", chapters->head->height);
    /*printf("%s\n", chapters->head->next->title);
    printf("%s\n", chapters->head->next->next->title);
    printf("%s\n", chapters->head->next->next->next->title);*/
}

Everything loads in the list fine but inside the loop to add the words to the tree inside the list the root is always returned as null when trying to print. I'm using a standard insert and I don't see any pointing problems even though from the output that is most likely what it is. Any help at "pointing" out my blind spots would be appreciated. The pun is stupid, I'm drunk on programming.

[Salem]

Try say
pCurrent->left = addTreeNode(string, pCurrent->left);

You're ignoring the all important return result when you actually create a new node.
There's a lot of ignored return results.

And remove all those malloc casts, this is C.