The boy was injured while riding his bicycle at about 8:30 a.m. with two friends within the Montgomery Pinetum Park, a 91-acre public park in the Cos Cob section of Greenwich.
The boy lost control of his bicycle while leaving the trail and fell off his bicycle, police said. He struck his head on a rock and suffered a severe head injury, police said. The youth was not wearing a safety helmet.
One of the other youths dialed 911 from his cellphone and personnel from the Greenwich Police Department and the Greenwich Emergency Medical Service were dispatched. The youth was quickly located within the park, was provided medical assistance, and transported initially to the Stamford Hospital Emergency Room.
He was later transferred to Yale-New Haven Hospital. As of 3:45 p.m. Saturday was listed as stable but in critical condition and in intensive care, police said.
Parents and/or guardians of the three youths involved have been notified.
The names of the juveniles were not released.
The Greenwich Police Department is investigating the incident.
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