A 12-year-old boy fatally stabbed his teenage brother in the chest in the family's Minnetonka home, according to police.

The killing of the 16-year-old occurred about 8 p.m. Saturday at an apartment in the 11300 block of Fairfield Road, police said.

Officers arrived, resuscitation efforts were made, and the teen was taken to North Memorial Health Hospital in Robbinsdale, where he was pronounced dead.

"We know there was some sort of an altercation between the two boys," Minnetonka Police Chief Scott Boerboom said at a news conference Sunday.

Police said the 12-year-old used a kitchen knife to kill his brother, whose identity has not been released.

"The mother and other family members were home at the time of the incident," a police statement read. "Police are working with the family to determine the circumstances that led to the stabbing."

"It's a tragic situation," Boerboom said. "This family was torn apart."

The 12-year-old was not injured but was taken to the same hospital for evaluation. His identity also has not been released. He is now with family, not in police custody, Boerboom said.

Police said they had never responded to the family's address before, but the mother had once called police about a theft.

Staff writer Erin Adler contributed to this report.