Three children have now died from injuries suffered last week in a St. Paul house fire, and a fourth remains in critical condition, their father said Saturday.

Pa Cheng Vang confirmed the deaths of 5-year-old twin daughters Ntshiab Si and Siv Ntshiab and 4-year-old son Mauj Tshau Ntuj in the wake of Wednesday's blaze.

He said his 1-year-old son, Mauj CagTxuj Vaj, was in critical condition, and family members said Vang's wife remains in serious condition at Regions Hospital, occasionally opening her eyes for nurses.

Vang said a son, 6-year-old Cag Kub Vaj, and daughter, 3-year-old Hnub Qub Vaj, are no longer in critical condition and are showing signs of strength.

His wife Ker Lor and all six children — three boys and three girls — were hospitalized after the early-morning fire at their home in the 1200 block of Arkwright Street N. in the Payne-Phalen neighborhood.

"As a parent, I believe that you all know the feeling when your child's sick, when your child's burnt," Vang said at a news conference as he held back tears. He encouraged other families to practice fire safety.

"Moving forward, I hope that everyone can start [that] practice so that I never see any news on TV or social media that your family has the same condition as my family."

Alerted by neighbors to the fire around 1:30 a.m., emergency crews arrived at the family's home to find black smoke billowing from the windows and doors. Neighbors were rushing in to help, watching from afar as firefighters performed CPR on Vang's wife and children.

Police notified Vang at work, and he rushed home to learn that his wife and children were unresponsive. One twin daughter died later that day.

Officials are investigating the blaze but said its cause is not suspicious.

Mayor Melvin Carter embraced members of the Vang family at Saturday's news conference, holding one person who sobbed into his arms. Carter said he knows the Vangs personally — Vang's wife interned at his office years ago. He took pictures with the family at the time and held their children.

Carter said the tragedy affects all of St. Paul.

"You've endured all of our worst nightmare," Carter said, pausing to look at pictures of the Vang family lying on a table before him. "There's a family in our community that needs help, and I'm looking forward to seeing our community step forward."

Vang's aunt, Yong Vang, said the family has not yet discussed funeral arrangements. Some donations are being made on an online fundraiser, but Vang said plans are to open a bank trust account for other donations.

Brian Xiong, program director of the Hmong 18 Council, challenged more residents to show support.

"As a Hmong community, let's come together," said Xiong, whose organization was launched after a distraught Hmong woman killed her six children. "Support Mr. Vang and his children at this time.

"If you can donate whatever you can, please do," Xiong said, holding Pa Cheng Vang as tears welled in his eyes. "He not only lost his children, [but] his house [and] his hope."

Star Tribune staff writer Paul Walsh contributed to this story.

Correction: This article has been updated with the correct spellings of surviving children Cag Kub Vaj and Hnub Qub Vaj.