Two people were found dead and two others were injured Thursday in an early morning house fire in Kentucky, authorities said.

Firefighters were dispatched about 3 a.m. and arrived to find a heavy blaze at the one-story home, a statement from the Louisville Fire Department said.

Two people were found dead inside the home, the statement said. Fire crews rescued another person and a fourth occupant got out before emergency personnel arrived, officials said.

Both injured people were treated and taken to a local hospital. Updated conditions were not immediately available.

The blaze caused extensive damage to the home and minor damage to a neighboring house, officials said.

An preliminary investigation found no working smoke detectors in the home, the fire department said. The cause of the blaze is under investigation.