Four elderly residents were treated for smoke inhalation after a kitchen fire in an apartment building on Edward Street Thursday.
A cigarette discarded in a plastic bucket is believed to be the cause.
But it's not clear if inhaling the smoke from the burning plastic directly led to the injuries suffered by the four seniors.
"They were probably in the suites in the same hallway as the kitchen fire," Assistant Fire Chief Ian Josephson said.
As a "precaution" BC Ambulance paramedics sent the four to Chilliwack General Hospital for observation, he said.
There were no other injuries reported among the residents who evacuated the three-story building after the alarm system was activated at 12:12 p.m.
Thick, black smoke on the ground floor was seen by firefighters upon arrival.
Fire crews extinguished a fire in the kitchen area of one of the suites, and the smoke was ventilated.
"There is extensive fire damage to the kitchen area with considerable smoke damage to the remainder of the one suite and hallway," Josephson said.
Earlier on Thursday, a kitchen fire was reported in a single-wide manufactured home in the 6000-block Vedder Road.
The owner was not home at the time of the 7:59 a.m. fire, and no injuries were reported.
Fire damages were limited to the kitchen area, with extensive some damage to the rest of the trailer.
Last year, several kitchen fires were reported in Chilliwack, and a cigarette stubbed out in a patio planter caused fire damages in two adjacent townhouses.
So far, there have been no serious injuries caused by the fires, but a kitchen fire in a mobile home on Watson Road last August caused the death of a family's pet cat.
Leaving stove-top meals unattended in the kitchen was one of the leading causes of residential fires in Chilliwack and North America last year.
Chilliwack fire officials are again reminding the public to always extinguish smoking materials in a deep, non-combustible ashtray.
"Make sure cigarette butts are wet before you put them in a garbage container," Josephson said.