A 15-year-old teenage girl first reported missing earlier this week has been found dead, authorities said.

Alicia K. Casares was pronounced dead at 3:50 p.m. Thursday at her home in the 600 block of West 151st Street in East Chicago, according to a Lake County coroner's news release.

The 15-year-old's manner and cause of death are pending.

In a news release Thursday night, East Chicago police said they were dispatched about 2:40 p.m. to the home, where they were met with a family member, who said they found Casares unresponsive in an upstairs bedroom.

Police said they could not confirm an official cause of death Thursday night, adding that they are considering this a death investigation.

Casares was first reported missing Monday by her mother, East Chicago police said earlier this week. The mother told police she last saw her daughter Sunday night.

Juanita Pena, of East Chicago, told The Times her daughter was Casares' friend through school. Pena said she and others had been actively looking for the missing teen.

On Thursday, Pena said the plan was to put together a search party, but then she got a call from the family this afternoon that the search was no longer needed.

"I was just shocked and devastated. We're just trying to take it all in," Pena said.

The circumstances surrounding Casares' death were not immediately known Thursday night.

Pena said the 15-year-old attended Bishop Noll as a sophomore and played on the soccer team. Pena said the girl's family has asked for privacy.

The coroner's office, East Chicago police and Lake County's Crime Scene Investigative Unit assisted at the scene.

Anyone with additional information about this case should contact Detective Miguel Pena at 219-391-8306.