(CNN) -- Six members of an Indiana family -- four children and their parents -- were killed in a house fire this weekend, the Indianapolis Fire Department said Sunday.
Investigators are trying to determine what caused the fire on Saturday. No smoke detectors were found in the home.
Family members told CNN affiliate WRTV that Leo Guerra tried to save some of his family from the burning home before becoming a victim himself.
Guerra, 47, his wife, Brandy, and two of their children -- 8-year-old Esteban and 11-year-old Blanquita -- died Saturday at the scene. The two other children -- 14-year-old Miranda and 6-year-old Fuente -- died Sunday.
Neighbors, friends and extended family came to the site of the family's home and laid flowers at a temporary memorial Sunday.
One of those visitors was Indianapolis Mayor Greg Ballard, who called the deaths "tragic."
The Indianapolis Fire Department said this is the largest single loss of life for a family because of fire that the department has seen.