Thirty-five Honolulu firefighters responded to a house fire in Lanikai Thursday afternoon, according to fire officials.

The two-alarm fire started just after 1:30 p.m. on Mokulua Drive.

When crews got to the scene, the house was fully engulfed in flames, according to fire officials.

All three occupants, two adults and a teenager, were not home at the time of the fire.

Emergency Medical Services officials said an 18-year-old woman, who tried to help put out the fire with a garden hose, was hospitalized in serious condition due to smoke inhalation.

"We just saw black smoke going crazy in the sky, and we could see just from three houses down -- flames rolling over the house," said witness Greg Ebbert.  "It was intense.  You could feel the heat."

Flames appeared to be extinguished at around 2:20 p.m.

The cause is under investigation.

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