Cause of 6-year-old girl's death remains a mystery one day after officers searched her family's home

LONGMONT, Colo. - The cause of a child's death that prompted a hazmat  response from police in Longmont remains a mystery.

Monday, officers dressed in hazardous materials gear searched her family's home. Tuesday, a memorial developed outside.

Family members say 6-year-old Lluvia Espinoza died suddenly Monday morning. The cause remains unknown, but it was preceded by a high fever.

"She was so sweet, her beautiful eyes," said Rigo Holguin, the girl's uncle. "She was a happy little girl, always active, always playing around."

Holguin says the family is as shocked as everyone else.

"We don't know actually what happened, but pretty soon we will know," he said.

Police and the family are now awaiting autopsy results and say the child had experienced flu-like symptoms.

"Her mom is still very sad. Very, very sad," Holguin said.