A 15-month-old boy died Thursday after falling from a window on the seventh floor of an apartment building, authorities said.

The death appeared to be accidental, but detectives were trying to determine whether an adult was at the suburban Detroit apartment and whether the window had a screen, police spokesman John Harris said.

The toddler and his 7-year-old brother had been in a bedroom together but the older boy left and returned to find his brother missing. When he looked out the window, he saw the toddler lying in the parking lot, Harris said.

Paramedics rushed the toddler to an area hospital where he was pronounced dead.