A child is in critical condition after a car unexpectedly accelerated, hitting three people at a park in Mercer County.

Hamilton police responded to Veterans Park on Klockner Road on Monday at about 4:35 p.m. after reports of people being struck by a vehicle in the parking lot.

According to police, a preliminary investigation shows that a Hamilton man driving a silver BMW SUV was trying to park the car in one of the spaces in the parking lot when he “accelerated unexpectedly” after mistakenly hitting the gas instead of the brake pedal.

“The vehicle proceeded over a grass median and struck three pedestrians who were in the process of exiting their vehicle,” police said in a statement.

A man, woman and child — all from Trenton — were injured and transported to Capital Health Regional Medical Center for treatment. The adults are in stable condition, and the child is listed in critical condition, police said.

Police temporarily closed the parking lot at Veterans Park while the investigation took place. Investigators are asking anyone who may have witnessed the crash to contact the Hamilton Police Traffic Unit at 609-581-4000.