EAST MOUNT AIRY (WPVI) -- Philadelphia police are investigating a shooting that left four men, one critical, injured in East Mount Airy.The shooting happened just before 8 p.m. Sunday in the 1100 block of East Woodlawn Street.All four victims were taken to Einstein Medical Center.The most seriously injured is a 33-year-old man who is in critical condition after being shot in the left leg, police said. The others - ages 34, 21 and 15 - who were shot in the left bicep, right leg and right thigh, respectively, are all in stable condition.So far, no arrests have been made.