Sudbury, MD – One man died and three other people were hospitalized yesterday after breathing in high doses of carbon monoxide from a diesel generator running inside the home’s closed attached garage, authorities said.

Firefighters said yesterday that there was no electrical service in the victims’ rented house at 23 Old County Road. A woman woke up during the early morning hours, barely able to breathe, and called 911 on her cellphone, Sudbury police said.

Police and firefighters arrived around 3:30 and immediately turned off the generator and removed the remaining residents, who were unresponsive, from the house.

Sudbury Fire Chief Ken MacLean said he was baffled that a gas generator had been running inside the home.

“You keep hearing, especially after the ice storm of 2008, about how dangerous it is to run generators in the house,’’ he said in an interview at the scene yesterday morning. “It leads to tragedy.’’

MacLean said that the woman, identified by police as Aida Leone, 42, was treated and released at MetroWest Medical Center in Framingham, and two men, Juraci Almeida, 50, and Elvis Dasilva, 20 were airlifted to Massachusetts General Hospital in critical condition with life-threatening illnesses. A third man was taken to MetroWest Medical Center, where he later died. His name was not released yesterday.

MacLean said power was out in the home, but he did not speculate why. He said the four residents were renting the home.

Michael Durand, a spokesman for NStar, confirmed the power was off but could not elaborate on a reason due to privacy concerns.

“We’re just shocked and saddened,’’ MacLean said. “It’s a real tragedy.’’

Fire officials said there was no evidence of working carbon monoxide detectors in the home, which are required under state law.

The state fire marshal’s office said the number of carbon monoxide-related calls has risen every year since the 2006 enactment of Nicole’s Law, which requires the detectors. The regulation was named for a 7-year-old Plymouth girl who died from carbon monoxide poisoning in January 2005.

“Carbon monoxide is called the silent killer or the invisible killer because it is odorless and colorless,’’ said State Fire Marshal Stephen Coan. “I cannot stress enough how important it is to install carbon monoxide as well as smoke alarms in your home. If you have not done so, today would be a good day to do so.’’