A carbon monoxide scare at a southeast Calgary home Tuesday night ended with nine people in hospital.

The fire department was called to the Riverbend home just before 10 p.m., where they found two men working on their motorcycles in the attached garage.

CO levels in the garage were negligible likely because the doors were open, but crews found carbon monoxide levels of 170 parts per million in the home. Anything over 35 is considered excessive and more than 100 is considered dangerous.

Nine people were removed from the home — four children and five adults — and taken to hospital for assessment.

"Despite that it's presumed the idling motorcycles were the cause of the increased levels of CO, fire crews remained on scene to ventilate the home and test the furnace and hot water heater to confirm that they were not contributing to the poisonous atmosphere," fire officials said in a release.