Video showed flames tearing through a 2-story home on Park Avenue in Seaford.
Officials say it started just before midnight.
Crews arrived to find heavy fire and smoke pushing through the roof.
It took them an hour and 45 minutes to get the blaze under control.
One person was taken to an area hospital to be treated for smoke inhalation.
Initial reports indicated an e-bike may have sparked the fire.
The fire is being investigated by the Nassau County Fire Marshal's Office and NCPD Arson/Bomb Squad.
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