El Dorado police are investigating the second mysterious death in three days at the same house.
Emergency responders were called to a house in the 800 block of South Emporia shortly before 9:20 a.m. after a man was found not breathing in a basement bedroom.
David P. Long, 41, was pronounced dead at Susan B. Allen Hospital at about 10 a.m.
Authorities had gone to the same house on Monday for a similar incident. Long's brother, 37-year-old James Drake, was found unresponsive and later pronounced dead at Susan B. Allen.
Authorities are awaiting toxicology results before making a determination on why Drake died, El Dorado Police Chief Tom Boren said in a prepared statement.
Investigators are looking for potential gas leaks, but the house is an all-electric home.
"Examination of the premises by fire investigators does not support any gas or other volatile gas involvement," Boren said.