ST. PAUL, Minn. (AP) — A fourth child has died of injuries suffered in a fire at a home in St. Paul, officials said Tuesday.

Police Sgt. Mike Ernster said 1-year-old Mauj CagTxuj Vaj died at Regions Hospital over the weekend, the Star Tribune reported.

Ker Lor, 28, and her six children — three boys and three girls — were found on the first floor of the home by firefighters and hospitalized after the early morning fire Jan. 3 in the Payne-Phalen neighborhood, according to the Star Tribune. Pa Cheng Vang, the children’s father, was at work at the time.

Their 5-year-old twin girls and 4-year-old boy also died.

Vang said over the weekend that their 6-year-old son and 3-year-old daughter were no longer in critical condition and were showing signs of strength, according to the Star Tribune. Their mother also continues to recover at Regions.

The fire broke in a living room on the main floor that the home’s occupants would have had to go through to escape, Deputy Fire Chief Roy Mokosso said Tuesday.

The cause of the fire was accidental, but it remains under investigation, Mokosso said earlier. The home had working smoke detectors.