An FDNY EMT was busted for ransacking his dying landlord’s apartment — stealing more than $30,000 in items — after he helped prepare him for transport to the hospital, authorities said.

Javier Rosario, 29, jumped into action to help his colleagues, who responded when the elderly landlord suffered a medical episode Jan. 5 inside the apartment on 84th Street near 19th Avenue in Bensonhurst, cops said.

But then, while the other EMTs rushed the landlord to the hospital, Rosario ransacked the apartment, stealing about $33,000 in laptops, jewelry, money and other items, police said.

The landlord died at the hospital, cops said.

Rosario was busted around 7:40 p.m. Thursday, after the senior’s widow found video showing him in the apartment, police said.

He was charged with burglary and criminal possession of stolen property, authorities said.

The FDNY said an investigation is underway.

He has served with the FDNY for two years and works in Brooklyn, a spokesman said.