NEW YORK -- A New York Army National Guard Soldier who died in a massive apartment house fire in the Bronx on Dec. 28, is being credited with saving four lives, rescuing people three times before he returned to the building and did not come out.

Detectives assigned to the New York Police Department's 48th Precinct reported that Pfc. Emmanuel Mensah entered the apartment building at 2363 Prospect Avenue at least three times to assist other residents and family members after he initially escaped the fire.

Mensah had lived in the building and recently returned home from military training in Virginia.

Twelve New York City residents died in the fire which began after 6:30 p.m. Fire department investigators say the blaze was started by a young boy playing with a gas stove. The fire spread after the child's family escaped the apartment and neglected to close the apartment door behind them, according to investigators.

Local media reports said the fire was the most destructive residential fire in the city in decades.

New York City Mayor William DeBlasio praised Mensah in a Twitter message sent on Dec. 30:

"Private Emmanuel Mensah was a first generation immigrant, a soldier, and a New Yorker. He gave his life rescuing his neighbors in the Bronx fire. His heroism exemplifies the best of our city. Rest in peace," his message says.

When firefighters were able to enter the building they discovered Mensah's remains and believe that based on the location of the body, he was still seeking to rescue people, according to statements provided to New York Army National Guard officials.

Local residents who spoke to members of the New York Army National Guard also reported that Mensah had risked his life to save others.

Secretary of the Army Mark T. Esper approved the posthumous award of The Soldier's Medal for PFC Mensah on Jan. 1, 2018.

The Soldier's Medal is the Army's highest award for heroism that occurs outside of combat.

"Private 1st Class Mensah's heroic actions are in keeping with the highest traditions of military heroism and selfless service and reflect great credit upon himself, the New York Army National Guard and the United States Army," the award citation says.

Gov. Andrew Mr. Cuomo approved the award of the New York State Medal for Valor posthumously on Jan. 2, 2018.

The award is New York State's highest military award and is presented for acts of heroism on and off the battlefield.

"His courageous and selfless act in the face of unimaginable conditions are consistent with the highest traditions of uniformed service and deserving of the highest possible recognition," his citation says.

Mensah, who enlisted in the New York Army National Guard in December 2016, had recently completed his Advanced Individual Training to serve as a wheeled vehicle mechanic.

He was slated to begin drilling with the New York Army National Guard's 107th Military Police Company this month. The 107th Military Police Company is based at Fort Hamilton in Brooklyn. Mensah was still assigned to Company A of the New York Army National Guard's Recruiting and Retention Battalion prior to joining the 107th MP Company.

His family immigrated to the United States from Ghana and Mensah was a permanent legal resident at the time of his enlistment. He became a naturalized United States Citizen on Sept. 21, 2017.

Mensah was an excellent Soldier, said Staff Sgt. Ruben Martinez-Ortiz, who recruited him.

"I knew from the moment I met him his heart was as big as our National Guard family," Martinez-Ortiz said. "He was ready to serve our nation and community. Pfc. Mensah was the embodiment of what our Army Values stand for."