KANSAS CITY, Kan. -- An early Monday morning deadly fire has now turned into a murder investigation.
It happened on North Mill Street near Central Avenue in Kansas City, Kansas, around 4:30 a.m.
"I don't know if they burned the house down to erase evidence, but my niece, nephew and sister-in-law didn't deserve this," Ana Rodriguez said.
Family members tell FOX4 the victims are a 31-year-old mother of four, along with her 14-year-old daughter and 10-year-old son.
KCK firefighters working near Mill Street and Central Avenue saw smoke coming from the attic of a house. Inside, they found the woman and two children.
"You don't expect to wake up to stuff like this. It's pretty sad," neighbor Nichole Varela said.
Ana Rodriguez said her former sister in law, nieces and nephews live in the home that burned. She'd tried calling them just Sunday night.
"Never in my life thought she wasn't answering me because she was gone," Rodriguez said.
Ana said Yazmin Rodriguez was a hard-working single mom. Her two youngest children are spending the holidays with their dad. Yazmin, along with her 14-year-old daughter Amerikha and 10-year-old son Jeancarlos, were all killed, then their home burned.
"They were so loving. They were the happiest kids ever. I don't why anybody would want to hurt them," Ana Rodriguez said.
Ana and her siblings are now desperate to get their brother, who is father of the children who died, back to KCK from Mexico.
"I'm trying to get whatever I can so he can come say goodbye to his kids," Rodriguez said.
The family and investigators are now searching for clues about who killed the mother and children and how the fire started.
"I want justice. If anybody saw anything, anybody going inside the house, speak up. Let anybody know," Rodriguez said.
Police have been talking with neighbors and looking for possible security video of anyone who might've been in the area around the time of the fire.
There is a Go Fund Me page set up to help the family.