A 16-year-old tried to protect his 4-year-old brother from a car that jumped a Bedford-Stuyvesant curb yesterday afternoon and struck them on a sidewalk. Dwayne Jackson suffered a broken arm while Dillan, a pre-K student, is in critical condition, with a broken leg and pelvis (the 4-year-old also had his lungs drained of blood). One witness said, "I heard the impact and I looked and then I saw the child spread out all over the street. I saw this kid like a rag doll on the ground so I went downstairs and started to pray for him." Others say the driver of the black Mercedes, which crashed into a tree, ran away, but not before, according to a witness who spoke to the Post, "He held the little boy - cradling him in his arms - and handed him off." Police brought in helicopters and K9 units (pictured is one dog with the suspect's shoe) to track the suspect. The boys' mother told the Daily News, "We're trying to keep it together. It looks like they're both going to make it."