CHATTANOOGA (WRCB)-- Chattanooga Police are investigating a deadly case of abuse, involving two little boys.

Police Sergeant Jerri Weary tells Channel 3, two boys, ages 3 and 4, were taken to Erlanger Monday.

Weary says the four-year-old was pronounced dead on arrival, and the other child was taken to ICU.

She says preliminary findings show the both children suffered abuse, but says an exact cause of death is unknown.

Police are currently interviewing boys' mother and her boyfriend.

Stay with for updates to this developing story.