Three people in North Laurel were hospitalized after they were found with elevated levels of carbon monoxide, officials said.

Shortly after 4:45 a.m. Tuesday, firefighters and paramedics went to a home in the 9700 block of Brevard Street and found three people with high carbon-monoxide levels. A man was taken to a hospital in critical condition, and two women were taken to a hospital in serious condition, according to Howard County fire and rescue officials.

The occupants were using a generator because they lost power during the storm, and the generator was not being ventilated properly, a fire and rescue spokesman said. The generator was found in a closed garage, and a door from the garage to the house was open.

According to the National Fire Protection Association, generators should be run outside, away from doors, windows and vent openings.