title: Leaflet map won't fit bounds
body: <p>I'm trying to fit a map to bounds defined by a 2D array.  I keep getting the error <code>Error: Bounds are not valid.  leaflet.js:5:21909</code> even though the markers are added to the map and are valid coords.</p>
  
  <pre><code>var map = L.map('map', { zoomControl:false });
  L.tileLayer('http://{s}.tile.osm.org/{z}/{x}/{y}.png', {
      attribution: '&amp;copy; &lt;a href="http://openstreetmap.org/copyright"&gt;OpenStreetMap contributors&lt;/a&gt;'
  }).addTo(map);
  
  
  
  map.setView([0, 0], 2);
  
  var markers = new L.FeatureGroup();
  map.addLayer(markers);
  
  
  function drawResults(){
      // get offer keys
      var offers = new Array();
      var articles = [];
  
  
      offersRef.once("value", function(snapshot) {        
          var offerKeys = Object.keys(snapshot.val());
          for (var i=0; i&lt;offerKeys.length; i++){
              var offer = snapshot.val()[offerKeys[i]];           
              var lat = offer.lat;                
              var lng = offer.lng;
              console.log(lat);// outputs 33.2321
              console.log(lng);// outputs 101.1234
              offers.push([lat, lng]);
              var marker = L.marker([lat, lng]).addTo(markers);
          }
  
      });
      map.fitBounds(markers.getBounds());
  
      }
      console.log(offers);    
  
  }
  
  drawResults();
  </code></pre>
  
  <p>Can anyone see what I'm doing wrong?</p>
  
  <p>Edit: 
  Console logs </p>
  
  <pre><code>35.0721909  app.js:350:13
  -106.48798399999998  app.js:351:13
  35.0526641  app.js:350:13
  -78.87835849999999  app.js:351:13
  </code></pre>