ONTARIO -- After three days of fighting for his young life, a 7-month-old boy finally succumbed to injuries Friday and Ontario Police investigators are searching for the person responsible for the infant's death.

Lukas Clark of Rancho Cucamonga was declared brain dead Friday afternoon, according to San Bernardino County Coroner officials.

Ontario police and fire personnel were called out to a home in the 800 block of W. J Street in Ontario early Tuesday morning for an infant not breathing,

Investigators and paramedics determined the infant, later identified as Lukas, had suffered physical injuries, according to police reports.

The child was taken to Montclair Hospital Medical Center then transferred to Loma Linda University Medical Center Children's Hospital where he was remained until he was pronounced brain dead on Friday, officials said.

Anyone with information about the incident is asked to contact Detective Jeff Wentz at 909-395-2715.