A laborer, identified as Gregor Pangilinan, was hit by falling debris while evacuating his personal belongings from his burning house in Barangay Fortune at about 11 p.m. on Sunday.
Pangilinan was sent home after undergoing treatment for a fractured left arm at a hospital.
Fire prober SFO2 Jesusito Ada said the fire started at the second floor of the house occupied by Michael Escobar in Barangay Fortune.
Residents tried to put out the blaze with pails of water but failed, he said.
Ada said strong winds fanned the fire toward adjacent houses made of light materials.
A total of 23 firetrucks from the city and its nearby towns and cities responded to the fire scene.
At least seven houses were razed to the ground before firemen put the blaze under control, 20 minutes later.
City Mayor Marides Fernando rushed to the fire scene and gave the affected families temporary shelter at the F. Bautista Elementary School in nearby Barangay Concepcion Uno.
Barely six hours later, another fire broke out at the ground floor of the house occupied by a certain Lilibeth Balbona in Doña Petra Subdivision, Sitio Tumana, Barangay Concepcion Uno.
Ada said a total of 36 houses, which were also made of light materials, were totally destroyed.
A total of 25 firetrucks responded to the fire and put the blaze under control at 6:52 a.m.
The 36 affected families were also evacuated to the F. Bautista Elementary School.
Ada said they are still investigating the cause of the two fires, which both reached the fourth alarm.