A 4-year-old boy fell from a ninth-floor window at a Silver Spring apartment building Thursday afternoon, Montgomery County police said.

Officers and fire department rescuers responded to the 8800 block of Piney Branch Road for a report of an injured child about 3:15, officials said. Authorities discovered that 4-year-old boy fell from a 9th floor apartment window.

The child was taken to Children’s Hospital in serious condition, police said.

Detectives were investigating the circumstances of how the child fell, officials said.