10:10 am UPDATE: The person on the Sierra Ave bridge has been taken into custody and all lanes of the freeway are back open!
The 10 freeway is shutdown in both directions at Sierra Ave in Fontana because of what may be a potential jumper situation. A person is currently standing on the bridge. The back up on both sides of the freeway is for miles. Images on Sigalert shows the person sometimes standing and then sitting dangling their feet over the side of the edge of the overpass.
Do your best to avoid the 10 through Fontana if at all possible.
Developing story... For more follow Robin Winston on Twitter.