PHOENIX — Three children have been pronounced dead inside a home, according to Phoenix police.

A relative who lives at the residence called police Monday and responding officers found a 7-month-old girl, 2-year-old girl and 3-year-old boy, authorities said. The children were unresponsive and pronounced dead after officers administered CPR and fire officials provided first aid.

Police were interviewing the mom, dad and another relative, according to authorities. There was no obvious trauma to the children, and relatives indicated illness may have been a factor, police said.

It’s too early to determine how the children died, police said. An investigation is ongoing.