'Overheated' Hillary Clinton leaves 9/11 memorial early

NEW YORK (AA) - Presidential nominee Hillary Clinton was "feeling great" hours after leaving early from a 9/11 observation event at ground zero due to feeling "overheated".

The Democratic candidate and her Republican rival, Donald Trump, joined thousands of others gathered at the National September 11 Memorial & Museum to commemorate the 15th anniversary of the worst terrorist attack on U.S. soil.

A video posted on Twitter appeared to show the 68-year-old former Secretary of State struggling to stand and being helped into a waiting vehicle. Clinton left early to rest at her daughter Chelsea's apartment in lower Manhattan after she said she felt "overheated", according to a statement by Nick Merrill, her press secretary, who said later that she was "feeling much better".

As she exited the apartment building to return home in Chappaqua, New York, just north of New York City, Clinton told reporters: "I'm feeling great, it's a beautiful day in New York.

Concerns about Clinton’s health have been raised by Trump who has cited a concussion in 2012 that required hospitalization. Trump and his aides have also said the former New York senator has appeared ill and tired while campaigning. Her doctor released a statement in July 2015 that said beyond taking blood thinners, Clinton is in “excellent” health.

The crowds an official at the event said numbered nearly 8,000, held a moment of silence at six separate times during the memorial, with the first one at 8.46 a.m. (1246GMT) when the first plane hit the south tower of the World Trade Center in lower Manhattan on Sept. 11, 2001.

The names of every victim of the attacks that day were read aloud, and mourners, some unable to hold back tears, laid wreaths in honor of their memory.

Clinton and Trump, who agreed not to speak during the ceremonies, kept low profiles and did not interact with each another.