firebase is retrieving deleted data from database
<p>I'm using firebase realtime database and it's working fine for some parts of my app.  I was going through a tutorial on youtube which populates a collectionView with users.  It uses NSDictionary to get the photo URL and username and puts them in the collection view for all users.  I deleted some of the users directly in the firebase console, and now have only one user.  For some reason it's still pulling the users that I deleted.  This is the collectionView file. </p>

<pre><code>import UIKit
import FirebaseDatabase

private let reuseIdentifier = "UserSearchCell"

class UsersCollectionViewController: UICollectionViewController {

var usersDict = NSDictionary?()
var userNamesArray = [String]()
var userImagesArray = [String]()

override func viewDidLoad() {
    super.viewDidLoad()
    DataService.ds.REF_USERS.observeEventType(.Value, withBlock :{
        (snapshot) in
        self.usersDict = snapshot.value as? NSDictionary
        for(userId,details) in self.usersDict!{
            let img = details.objectForKey("profileThumbUrl") as! String
            let name = details.objectForKey("username") as! String
            self.userImagesArray.append(img)
            self.userNamesArray.append(name)
            self.collectionView?.reloadData()
        }
    })

    self.collectionView!.registerClass(UICollectionViewCell.self, forCellWithReuseIdentifier: reuseIdentifier)
}

override func numberOfSectionsInCollectionView(collectionView: UICollectionView) -&gt; Int {
    return 1
}

override func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -&gt; Int {
    return self.userImagesArray.count
}

override func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -&gt; UICollectionViewCell {
    let cell = collectionView.dequeueReusableCellWithReuseIdentifier(reuseIdentifier, forIndexPath: indexPath) as! UserSearchCell

    let imageUrl = NSURL(string:userImagesArray[indexPath.row])
    let imageData = NSData(contentsOfURL: imageUrl!)
    cell.userImage.image = UIImage(data:imageData!)
    cell.userName.text = userNamesArray[indexPath.row]

    return cell
}
</code></pre>

<p>}</p>

<p>Shouldn't this always sync with the database?  Where are these deleted users coming from?  Also I didn't include the cell code because all it is is the imageView and Label actions being declared.  I ran into this problem before but my memory is bad and I don't remember why it was doing it or if I ever solved it.</p>