A teenage lifeguard resuscitated a 5-year-old boy pulled from a pool in Acton before first responders arrived Sunday evening, officials said Sunday.

The 19-year-old lifeguard was on a scheduled break just before 5 p.m. Sunday when the child’s floatation devices came off and he drifted into the deep end. He was submerged for about 30 seconds, according to officials.

The boy was unresponsive when the lifeguard pulled him from the water, according to the Acton police and fire departments. The 19-year-old then performed two rounds of CPR that got the child alert and breathing on his own before first responders arrived.

Acton first responders then arrived at the Bellows Farms condominium complex at 111 Davis Road just after 5 p.m. Firefighters transported the alert child to the hospital.

“Chief Cogan and Chief Arnum would like to commend the lifeguard who helped to rescue the boy from the water and performed CPR to get the boy breathing again,” they said in a statement.

Police said the child’s parents were nearby, and the incident was accidental, according to preliminary indications.