A 62-year-old man is dead and his brother is in custody in Brooklyn.
The 54-year-old brother was wheeled out his Coney Island apartment building by firefighters.
Police say he tried to keep them out of the apartment when they responded to an emergency call from inside.
Police say they overpowered him to get through the door and that's when he told them his older brother was dead in the bathtub.
Medical workers declared the older man dead on the scene and identified chemical burns on his chest and leg.
Neighbors said they knew the brothers as caring.
"They were quiet and one was hard working. He worked at Nathan's and they didn't bother anybody. They got along with anybody all their life," one neighbor said.
"I'm shocked. I can't believe that," another said.
The medical examiner is trying to determine a cause of death.
The other man is being held for a psychological evaluation.