MASSAPEQUA - Two teenaged sisters were seriously injured when they were struck by a car in Massapequa last night. Police say the sisters, ages 13 and 15, were struck on Merrick Road at around 8:30 p.m. They had just left a concert at John Burns Park when they were hit. Investigators say News 12 Long Island the 15-year-old suffered severe head trauma and was airlifted to the hospital. She is listed in serious condition and family members say she is currently sedated. The other teen broke both of her legs and required surgery. An Oyster Bay spokesperson says public safety officers patrol the park, but it's up to Nassau County police to monitor the roads outside of the park.