A fire that forced 40 people from their homes in Barrhaven Wednesday was caused by the "improper disposal of smoking material" and is estimated to have cost nearly $2 million in damage, Ottawa Fire Services said.

Flames broke out around 8:30 a.m. Wednesday on the exterior of a three-storey building along the 600 block of Chapman Mills Drive, between Woodroffe Avenue and Longfields Drive.

The fire caused extensive damage to eight of the 16 units inside the building.

UPDATE CHAPMAN MILLS: 3 1/2 multi unit residential building involved up to 16 units impacted. 911 call at 8:28 reporting fire on exterior of building. Fire investigator enroute. TY partners <a href="https://twitter.com/OttawaParamedic?ref_src=twsrc%5Etfw">@OttawaParamedic</a> for assisting w/ reportedly minor injury <a href="https://twitter.com/OttawaRedCross?ref_src=twsrc%5Etfw">@OttawaRedCross</a> <a href="https://twitter.com/Salvation_Army?ref_src=twsrc%5Etfw">@Salvation_Army</a> <a href="https://t.co/2JKYsoyKxL">pic.twitter.com/2JKYsoyKxL</a> —@OttFire

Fire investigators determined the cause of the fire to be accidental and said it originated at the rear of the building, near the lower balcony.

Evidence indicates the fire was caused by the careless disposal of a cigarette butt or similar item, Ottawa fire said Thursday.

Fire displaced 40 residents

The estimated dollar loss of the three-alarm fire is listed as $1,750,000.

No one was injured in the blaze.

The Salvation Army and the Canadian Red Cross have helped about 40 people who have been displaced.

Ottawa Fire Services reminded residents in a press release Thursday that smoking materials should never be thrown into recycling containers, dumpsters, planter pots or mulch.