A father who was picking up his two young children from football practice at an Oakland park was shot to death at the gathering where 60 children, aged 5 to 14, had been finishing up their drills, a witness told The Chronicle.

The victim, a former coach of an Oakland youth football team, had just arrived at Concordia Park on 64th Avenue on Wednesday afternoon when shots rang out, said Walté Orr, the president and coach of the Oakland Dynamites Youth Football program.