A seven-year-old boy has been rushed to hospital following a collision on a busy south Manchester road.The youngster is said to be in a serious condition following the incident on Plymouth Grove, in Longsight.The North West Ambulance Service sent a rapid response vehicle and an ambulance to the scene following the collision, which happened just before 8.30am this morning (December 1).The road is currently closed in both directions.The incident happened between Winterford Avenue and Nevada