FELTON, Del., (CBS) — The Delaware State Police are investigating a pit bull attack that they say killed a 4-year-old boy.

The incident happened around 4 p.m. Wednesday as a 4-year-old Camden boy and his mother were visiting a friend in the 900 block of Edwardsville Road, west of Felton.

READ MORE: Phillies' Bryce Harper Out Indefinitely With Broken Thumb After Being Hit By Pitch In 4-2 Win Over Padres

According to investigators, the mother, who is several months pregnant, and her friend were inside the home while the 4-year-old was outside playing in the yard around her friend’s three pit bulls of whom he’d been around numerous times in the past.

At one point, police say, the mother looked out the window and saw her son being attacked by the dogs.  While her friend called 911, the mother immediately ran out in an attempt to save her son and was also bit numerous times on both arms.

Two repairmen working at the house also attempted to save the young child by fending off the animals with PVC piping and helping the mother from the attacking dogs.

Medic units and troopers responded to the scene and began first aid on the young boy, before he was pronounced dead.

READ MORE: Philadelphia Weather: Tracking Possible Showers And Storms For The Fourth Of July Weekend

Investigators say the Office of the Chief Medical Examiner will conduct an autopsy to rule the exact cause and manner of death.

The 24-year-old mother was taken to Kent General Hospital where she is being treated for her injuries.

The investigation into this incident is ongoing and the three pit bull dogs were removed from the residence by the SPCA.

The status of the dogs is unknown at this time.

Police say the name of the 4-year-old victim is being withheld pending notification of family members.

MORE NEWS: Philadelphia Police Find Man's Body Burned, Possibly Shot In East Mount Airy