[Update Below: Hillary Clinton's doctor revealed that she was diagnosed with pneumonia on Friday.]Hillary Clinton abruptly left the annual September 11th memorial ceremony at Ground Zero this morning after she became "overheated."

Clinton leaving the ceremony (Getty Images)

And here's video of her getting into a van to leave the event.

Spokesman Nick Merrill said in a statement that Clinton left after 90 minutes, and went to her daughter Chelsea Clinton's apartment near Madison Square Park to recover. She is now reportedly "feeling much better."

It's unclear whether Clinton required any medical attention. Reporters and onlookers have gathered outside Chelsea's apartment.

An anonymous police source who claims they were 15 feet from Clinton told Fox News that they saw her "stumble off the curb," "appeared to faint," and get into a van, possibly losing one of her shoes in the process. The source added that she was "clearly having some type of medical episode."

Clinton's press pool was apparently unaware of her whereabouts when the incident happened.

Trump, who has repeatedly made insinuations about Clinton's health during the campaign (sparking a new conspiracy movement), told reporters he didn't know anything about the incident.

Just before noon, Clinton briefly addressed reporters as she left the apartment.

Update: After heading to her home in Chappaqua, Hillary Clinton was evaluated by her longtime physician Dr. Lisa Bardack, who released a statement about her suffering from pneumonia.