An 11-month-old boy was injured after his 35-year-old father reportedly grabbed him and jumped off the second-story balcony of an apartment complex on Waialae Avenue Sunday. Paramedics responded to the incident just before 11 a.m. Witnesses told police that after the father jumped, he left his infant son on the ground and started running away. Neighbors stopped him and held him until police arrived. Both the man and the baby are in serious condition. Police have opened a second-degree assault case.