A man was killed and three others injured Wednesday in an apartment fire in Park Manor on the South Side.

About 5:40 a.m., first responders received calls of a two-story apartment on fire in the 7000 block of South Wabash Avenue, according to Chicago police. Four people were pulled from the blaze, which was completely subdued about 6:20 a.m.

One person, a 48-year-old man, was pronounced dead at the scene, police said.

An autopsy Thursday did not rule on the cause and manner of his death pending further investigation, according to the Cook County medical examiner’s office. His identity has not been released.

Three others, one male and two females, were taken to the University of Chicago Medical Center for treatment, police said.

The Chicago Fire Department said two of the people were in critical condition, while the third was in fair-to-serious condition. Their ages were not immediately known.

An investigation found the fire started in a bedroom in the front of the home where the 48-year-old was found, fire officials said.

The cause was determined as an open flame ignition but the Office of Fire Investigation cannot rule out “careless use of smoking materials” as a likely cause, Chicago Fire Department spokesman Larry Langford said.