A National Guard member on assignment at the Capitol died after a medical emergency, defense officials said Thursday.

Joint Task Force District of Columbia is sad to confirm the death of a National Guard member serving with the U.S. Capitol security mission due to an apparent medical emergency, the National Guard Bureau said in the statement.

The individual was not on duty at the time, and the incident is under investigation, it continued.

It revealed no further details as officials are still working to notify the service members next of kin.

About 5,100 Guardsmen are deployed to the Capitol for the security mission there following the Jan. 6 attack on Congress, when supporters of former President TrumpDonald TrumpThe Memo: How the COVID year upended politicsBiden seeks his moment with pandemic address A year with the coronavirus: How we got hereMORE stormed the building in an unsuccessful attempt to disrupt the certification of President BidenJoe BidenManchin cements key-vote status in 50-50 SenateThe Memo: How the COVID year upended politicsPost-pandemic plans for lawmakers: Chuck E. Cheese, visiting friends, hugging grandkidsMOREs victory.

The number of Guardsmen has been culled following its height of 26,000 troops around Bidens inauguration, but the deployment has been extended to March 12, then again to May 23 over continued security concerns.

About 2,300 troops will stay in the Beltway to shore up Capitol police until the late spring date.

A number of controversies have arisen over the large number of service members in the area.

In January, lawmakers were outraged after some Guardsmen were forced to rest in a parking garage instead of inside the Capitol complex. They were quickly moved back inside after photos of them camped in the garage circulated online.

More recently, lawmakers in both parties have been expressing concern after guardsmen were sickened from undercooked food.

The Pentagon on Monday said that no moves are being made to remove any company from food service operations after the incident.