As one family in Prince George’s County recovered from carbon monoxide poisoning Monday night, a Howard County family was less fortunate after exposure left one man dead and his wife and teenage son in critical condition.

Woo Koo Sung, 48, was pronounced dead by fire and rescue workers at his home in the 2700 block of Old Saint John’s Lane in Ellicott City. Sung’s wife, Young Sin, 47, and his son, Jason, 17, have been hospitalized.

Sung’s daughter, who is 19, was staying with a friend when the incident occurred and was not exposed to the gas. When Sung’s daughter wasn’t able to reach her family by phone, she went to the house at approximately 10:45 p.m. She found her mother unconscious and called 911.

According to police, the family’s home lost power early Sunday morning during Hurricane Irene. Inside the attached garage of the single family home, police found a generator that was turned to the “on” position with the gas tank empty. There was a carbon monoxide detector in the home, but the batteries were dead. Police do not suspect foul play.

Also on Monday, a Fort Washington family was hospitalized after being exposed to high levels of carbon monoxide in their home — more than 30 times the amount that is considered healthy. One woman was found unconscious in the home. She and the three other victims are expected to recover fully.

Officials say people should never use a gas-powered generator indoors.

Click here for more on using generators and other tips on dealing with power outages and natural disaster.