Merced police said an adult and two children were asleep in an apartment when someone threw a Molotov cocktail through their bedroom window late Monday night.
One occupant was treated for smoke inhalation, investigators said. The firebomb caused an undetermined amount of damage to the interior of the apartment.
The incident, which is being investigated as an arson and attempted murder, was reported shortly after 11:30 p.m. in the 3100 block of Denver Avenue.
Anyone with any information about the case should call Merced police at (209) 385-4702.