The body of Lorenzo Ngo, 51, was discovered by firefighters at Room 601 of Josefa Building located at the corner of Padre Rada and Ilaya streets in Divisoria.
His wife Virginia, in her late 40s, was declared dead on arrival at the Metropolitan Hospital.
She died of smoke inhalation, according to the hospitals medical staff.
Arson probers said the fire started at around 4:30 a.m. inside the Ngos rented unit at the sixth floor of the building.
The fire reached the fifth alarm before it was placed under control at about 6:30 a.m.
The Ngos unit also served as warehouse for several bales of clothing materials.
The entire sixth floor was gutted by fire, according to investigators.
The couples children Lorilyn, Arlynel and Lester, and their nanny identified only as "Inday" managed to escape from the burning building.
Damage to property was initially placed at P100,000.
The cause of the fire is still being determined. Nestor Etolle