Flames broke out in the 4000 block of Hawaiian Terrace about 11 p.m. Tuesday.
The fire spread to six units before crews contained it.
Three adults and five children are displaced.
A child trying to kill a bed bug with alcohol and a match sparked the blaze, fire officials said.
“This was accidental. He wasn’t in there just playing with matches. It wasn’t the smartest thing, obviously, but he was trying to get rid of a bed bug,” said District 3 Chief Marc Monahan.
The American Red Cross is assisting the displaced residents.