San Francisco, CA- Eddy Choy-Santos, the 78-year-old San Franciscan found dead Monday of carbon monoxide poisoning, was remembered by residents in his building as a cheerful and chatty man who always had a friendly greeting for his neighbors.

The former manager of the five-story building at 816 Geary St. was found in his first-floor apartment, directly above the faulty water heater in the basement that leaked the gas that killed him and sickened eight of his neighbors.

“He was the sweetest man on the planet,” said neighbor Joey Wong. “He knew all of us, and he said ‘hi’ to everyone. He was like a saint.”

Wong, who has lived in the building for several years, said he smelled an unpleasant odor Monday before Choy-Santos’ body was found.

“It was a weird smell,” he said. “Not like gas. Very foul.”

Although carbon monoxide is odorless, other gases could have been released by the water heater as well, authorities said.

After fire officials allowed building occupants to return to their apartments Monday night, resident Mike Godfrey slept with his windows open. On Tuesday he still awoke with burning eyes and a headache, possible symptoms of carbon monoxide poisoning.

Godfrey said he was grateful for the unseasonably warm weather this week. “If it had been colder, all the windows might have been closed and a lot more people might have gotten sick,” Godfrey said.

Another resident, Diane West, also said she awoke with a headache Tuesday.

West discovered her neighbor Robert Spiller lying on the floor of his bathroom Monday night when she brought him his dinner.

“He was frozen. He couldn’t move,” West said.

She called 911 and firefighters took Spiller to a hospital, where he was in stable condition. Only later did firefighters return to the building in response to another emergency call from a relative who said he was worried about Choy-Santos, whom he had not seen for several days.

Like other residents, West said she had heard the steady alarm beep from a carbon monoxide detector since Sunday. But she said she did not recognize the sound and thought it was an alarm clock or a microwave oven.

There have been several instances this winter of carbon monoxide poisonings in people’s homes. Families in Novato and Vallejo were sickened New Year’s Day, and eight people were poisoned in a house near Redwood City last month. No one died in those cases.

The deadly San Francisco leak occurred the same day another carbon monoxide leak at a Cupertino apartment complex’s recreation center sickened eight people, including six Santa Clara County firefighters and paramedics, authorities said.

That incident occurred Monday afternoon at the Cupertino City Center Apartments at 20380 Stevens Creek Blvd., a fire dispatcher said. A faulty furnace or water heater was the likely cause.

The eight victims were hospitalized with symptoms that were not considered life-threatening.