Quito flooding toll raised to 27
The floods inundated homes, carried off cars, and swept away volleyball players and spectators on a sports field.
Two people remain missing, Quito security official Guido Nunez told reporters.
A massive clean up operation was under way, and rescuers were continuing the search for victims in the vicinity of the sports field that was first in the path of the sudden deluge.
Rain that drenched Quito for 17 straight hours caused flooding and surges of mud that damaged roads, agricultural areas, clinics, schools, a police station and an electric power substation.
Quito mayor Santiago Guarderas said Monday's rains overwhelmed a hillside water catchment structure that had a capacity of 4,500 cubic meters but was inundated with more than four times that volume.
Guarderas said Monday's downpour brought down 75 liters per square meter (1.8 gallons per square foot) following 3.5 liters on Saturday.
This is "a record figure, which we have not had since 2003," he added.
Three days of mourning were observed in Quito, a city of some 2.7 million people.
Heavy rains have hit 22 of Ecuador's 24 provinces since October, claiming at least 44 lives.