Police in Maplewood are investigating the death of an 18-month-old girl after they found her unresponsive with bruises on her body and face at a home on Thursday.

Paramedics tried to resuscitate the girl, who was found on the floor in a basement bedroom, but they were not successful.

Two men who were in the house, located in the 2500 block of Barclay Street, were detained and questioned. One of the men was arrested on suspicion of homicide and was in the Ramsey County jail. The other man was released.

The child’s name is not being released until next of kin can be notified. Police said the suspect, a 35-year-old man from Maplewood, is the boyfriend of the child’s mother and is not the biological father. The couple do not live together, police said.

Maplewood Police Chief Paul Schnell said "the level of injury was profound." Referring to bumps and bruises that can occur with any child in a mishap, Schnell said "this was far beyond that."

The call to police came from within the house, although it wasn't clear yet who made that call. Police have been called to the house before, but not for anything involving child abuse, Schnell said.

An autopsy was being conducted Friday, and police expect to present their findings to the Ramsey County Attorney's office for possible charges.

“Even while investigators work to determine exactly what happened to this little girl, no answer will mask the tragedy of her death,” Schnell said.

The Minnesota Bureau of Criminal Apprehension is assisting in the case.