Update (4/27 11:41 p.m.): NBC News reported that the whole situation stemmed from a man who stole a woman's purse and jumped the fence to get away
Update (4/26 4:46 p.m.): A Twitter account claiming to be Washington D.C. Fire and EMS just released the following tweet:
Update (4/26 4:32 p.m.): The lockdown has reportedly been lifted according to ABC:
Original Story: The White House has been placed on lockdown after a security incident, reports say.
CBS News is reporting that there might have been a possible fence jumper, and authorities are taking every precaution. The Secret Service has evacuated the North Lawn and areas around it.
We will update this story as details emerge.