A total of 169 areas were reported flooded in Metro Manila and Central Luzon.
Pagasa warned that continued moderate to heavy rain in Metro Manila and nearby provinces along the storm's path could trigger more floods and landslides.
The National Disaster Risk Reduction and Management Council said at least 2,103 families and more than 8,500 people had been affected in 109 villages located in the northern region.
Tropical Storm Maring is now over the West Philippine Sea after causing massive floods in Luzon and other parts of the Philippines, state weather bureau PAGASA said Wednesday morning.
"Some residents unfortunately did not heed the advice of local officials to evacuate to safer grounds", she said in a media briefing.
In Quezon province, a two-month-old girl was killed and seven others were injured when a concrete wall around a hospital collapsed on three houses in Lucena City after heavy rain soaked the soil at the wall's base, officials said.
Police also reported that a 12-year-old girl drowned in metropolitan Manila's Pasay city while bathing in a river during the heavy downpour.
Local officials ordered the evacuation of residents in some towns under floodwaters in Quezon, Laguna, Rizal and Batangas provinces, she said.
"These are in the 3rd district of Quezon, 4th district of Quezon, 2nd district of Cavite, 3rd district of Laguna and in the 1st district of the province Rizal", said NDRRMC Spokesperson Romina Marasigan.
The tropical storm is packing maximum sustained winds of 85 kph near the center, and gustiness of up to 105 kph.