(KRON) -- Two pedestrians in Antioch were critically injured in separate vehicle collisions Saturday night, according to police. The drivers in each incident fled the scene before law enforcement arrived. The first pedestrian-involved hit-and-run crash occurred around 6:50 p.m. in the area of East 18th Street and Phillips Lane. Arriving Antioch Police Department officers found a 54-year-old man with severe leg injuries. The victim was transported to a trauma center by air. Two killed, two injured in Antioch overnight crash Witnesses to the E 18th Street crash told officers the suspect driver fled in a dark gray sedan. Three hours later, around 9:57 p.m., Antioch PD responded to another report of a pedestrian struck by a driver at 801 Sunset Drive. The 63-year-old woman who had been hit was life-flighted to a trauma center with major injuries to her arms and legs. (KRON4) “Anyone who witnessed either incident, has surveillance or dashcam footage from the surrounding areas at these times, or possesses information regarding the fleeing vehicles is urged to contact Sgt. Green of the Traffic Unit at 925-779-6864,” Antioch police wrote. The hit-and-run crash investigations remain ongoing. ...read more read less