BUFFALO, N.Y. (WIVB) — Smoke inhalation has been revealed as what killed a mother and her daughter after a fire broke out on Weiss Street early Monday morning.

Buffalo firefighters were called to the home in the city’s Kaisertown neighborhood around 1:40 a.m. There, they say the stairs had been burned out and there were no working smoke detectors.

The two victims were found next to a window in a second-floor bedroom. Officials say the mother was 31, while family members say her daughter was about two-and-a-half years old. Earlier in the day, the Buffalo Fire Department had identified her as an infant.

Family members say the woman was Stephanie Schultz and her daughter was Stella Schultz.

Stephanie’s sister, Katie Host, spoke with News 4 about her family.

“Stephanie was a beautiful, kind soul. She would give the shirt off her back to anyone. She impacted many people that she had crossed paths with in her life and somehow she amazingly had time to keep in touch with a lot of them on the regular. Even if it was a simple message to say she was thinking of them. Her daughter and husband were her entire world! Everything she did was for them.”

“Stella was the happiest baby. She was so smart, strong-willed, and determined. She was also super funny, like witty funny. Somehow, even with how young she was, she still knew how to crack jokes and say all the right things to make us laugh.”

Four firefighters were hurt and taken to ECMC for treatment, but all have since been released.

The cause of the fire is under investigation, but Buffalo Fire Commissioner William Renaldo says it does not appear to be suspicious.

(Correction: An earlier version of this story listed the daughter as being an infant. This was incorrectly stated by fire officials during a conference that took place at 11:30 a.m. The girl’s age has been corrected.)

Evan Anstey is an Associated Press Award and Emmy-nominated digital producer who has been part of the News 4 team since 2015. See more of his work here and follow him on Twitter.