(WASHINGTON) -- A 3-month-old boy has died after being left in a hot car in Washington, D.C., authorities said.
Officers responded to a home shortly after 6 p.m. Tuesday and found the baby, Aaron Boyd Jr., unconscious and not breathing, D.C.'s Metropolitan Police Department said. Aaron was taken to a hospital where he was pronounced dead.
The heat index -- what temperature it feels like -- soared to 106 degrees in D.C. on Tuesday.
It was not clear how long Aaron had been left in the black Honda Accord, police said.
The investigation is ongoing, police said Thursday. An autopsy will determine Aaron's cause and manner of death.
Aaron is the 15th child to die from a hot car in the U.S. so far this year, according to national nonprofit KidsAndCars.org.