SWAMPSCOTT – MBTA Officer Jason Civello, 34, remains in stable condition following Tuesday’s accident on Humphrey Street in Swampscott.According to MBTA Spokesman Joe Pesaturo, Civello’s injuries are non-life threatening.The accident occurred Tuesday morning near the intersection of Humphrey Street and Puritan Road.According to the MBTA, Civello was in his police cruiser performing routine bus stop checks when the accident occurred.According to witnesses, Civello was on Humphrey Street when he started driving erratically and slumped over the wheel.Matt Kimball, who was driving alongside the MBTA cruiser when the accident occurred, said Civello accelerated suddenly and it appeared he was having a seizure. After knocking down a traffic light at the intersection, Civello smashed into several parked cars.James Dawson, who owns Small Wheels and Humphrey Motors, said several vehicles in his lot were damaged.Pesaturo said the accident remains under investigation.