A man was in serious condition at Lutheran Medical Center Sunday after jumping from a fourth floor window to escape a fire in the Red Hook West public housing apartment complex,officials said.

A total of 13 people, including two firefighters, were injured in the blaze at 75 Bush St. that appeared to begin on the fourth floor of the six-story building shortly before 6:37 a.m., said an FDNY spokesman. The jumper, estimated to be in his 50s, leaped from the building to escape flames after fire broke out on the fourth floor shortly before 6:37 a.m., said police, injuring himself on impact. The two firefighters and another injured person were taken for treatment to Long Island College Hospital and the rest declined treatment, according to the FDNY.

More than 100 firefighters battled the blaze with their progress hampered by having to use a "water relay" -- a condition usually prompted when the hydrant nearest a fire is not functioning -- but managed to bring the fire under control by 7:07 a.m.

The Red Hook West complex was badly damaged by Superstorm Sandy but it was not known if damage caused by the storm resulted in damage to the nearest hydrant.

The cause of the blaze remains under investigation.