A man who allegedly fatally stabbed his longtime girlfriend and stabbed her granddaughter before setting their apartment ablaze is in police custody in a hospital.

Police said Henry Maldonado, 55, fatally stabbed Carmen Irizarry, 60, and the victim's 9-year-old granddaughter in the apartment at the St. Mary's Park Houses around 5 a.m. Wednesday. 

The bloodied girl was able to run away and knock on doors for help, according to neighbors. She was rushed to a hospital for treatment for multiple stab wounds, and she was listed in stable condition.

Maldonado set the apartment on fire and barricaded himself inside, according to police, who said they found Maldonado holding a knife. The responding officers Tasered Maldonado, who had stab wounds that appeared to be self-inflicted, according to police.

Neighbors reported hearing an explosion when the windows blew out of the apartment.

They said they thought Maldonado, who was caring toward Irizarry's granddaughter, was married to Irizarry because the couple had been together since 2001 or earlier.

Irizarry, who worked as a caregiver at a group home, had custody of her granddaughter, according to a neighbor.

Maldonado, who is in critical condition, could face homicide and additional charges.