A United States Secret Service official said that the north side of the White House was placed on lockdown Monday due to the presence of a suspicious package, Reuters reported. The lockdown took place amid the Memorial Day holiday while President Barack Obama was home, and reporters were not allowed to exit the White House during the partial lockdown. According to the Secret Service official, the suspicious package was being checked for hazardous materials.
Associated Press reported that a woman threw an object over the White House's fence on Pennsylvania Avenue. A suspect was detained and handcuffed. Talking Points Memo reported that Hazmat suits were on the scene, as well as a portable decontamination unit. The incident occurred following Obama's return from Arlington National Cemetery, where he gave a speech in honor of Memorial Day. According to NBC Washington, the woman threw the object over the fence around 1:15 p.m. ET. The Secret Service is leading the investigation into the incident. A hazmat ops team, D.C. Fire's Special Ops, is in charge of analyzing the object that was thrown over the fence.
Lockdowns at the president's home are fairly common, as they are the go-to security response to any possible threat to the president. In fact, on April 27, the White House was placed on lockdown for a very similar reason as on Memorial day; CBS News reported that a man had thrown some personal belongings over the fence, according to a statement by the Secret Service.
There was a lockdown just the day before on May 26, CBS News reported, when a man jumped the west fence. According to a Secret Service statement, they determined that the man had been "fleeing from the scene of a robbery."
The White House was on lockdown more recently on May 20, when a man with a firearm approached a checkpoint, The Atlantic reported. According to the Secret Service, they repeatedly demanded that the man drop his gun, but the man did not respond. He was shot and critically injured.
Shortly after 3 p.m. ET on Monday, Steve Burns, anchor at WMAL News, tweeted a photo taken near the White House, saying that first responders appeared to be preparing to leave the scene:
Update: Late Monday afternoon, the security situation at the White House returned to normal as the lockdown was lifted. The metal object that the woman threw over the fence was determined not to be dangerous.