Duxbury, MD – A carbon monoxide leak forced the evacuation of a building in Duxbury on Monday, officials said. At about 10 a.m., a few people in the Percy Walker Pool building on St. George Street “thought they might have smelled something,” said Duxbury Fire Captain PJ Hussey. No one became ill, but the building was evacuated. The fire officials who responded detected in the air slightly elevated levels of carbon monoxide, a colorless, odorless gas that can be deadly. By 11:30 a.m., the cause of the leak had been determined to be a faulty heating vent related to the boiler, said Captain Robert Reardon.