Police say they found the weapons out in the open next to a bed when they went to knock on the door of the apartment where a neighbor said the 3-year-old girl lived. According to the station, police say the door was open an no one was inside. Police have yet to locate the girl's father.
"It's important to locate this individual and find out number one why he left his 3-year-old alone in such circumstances with weapons accessible to this 3-year-old," Detective Willie Moreno told CBS Miami.
The child was taken to the police department and authorities ordered the apartment complex be evacuated while they secured the grenade and guns.
Police say they believe the father, who has not been identified, knows authorities are looking to speak with him. They are asking him to go to the Miami Police Department.
The Department of Children and Families has reportedly been brought in to investigate the situation.