Updated 03/11/14 – 11:12 a.m.

CHICAGO (CBS) — A blind retired Chicago police sergeant was critically wounded when he was shot during a home invasion overnight.

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Police said the 73-year-old man was in his home at 115th Street and Avenue G shortly before midnight when two intruders gained entry through an unlocked door. They demanded to know where he kept his safe.

The man complied with their demands, but they shot him anyway, police said. His wife, who also was at home at the time, was not shot.

“I think it’s sick. It’s sick that someone would do that to someone elderly, who has served,” neighbor Tim Wedryk said. “He was a police sergeant for many years, retired. You know, someone who’s handicapped like that; it’s terrible that someone would do something of this nature.”

The two robbers fled the house and have not been seen since.

The man was taken to Advocate Christ Medical Center in Oak Lawn in critical condition, with a gunshot wound to the neck.

The couple’s caretaker, Eva Luna, said the retired sergeant has gone blind from Diabetes, and his wife suffers from dementia.

“He’s very ill; you know, has his medical conditions, and he needs 24 hours of guidance. His wife, she takes care of him in the evening,” she said.

Luna said she’s been working for the couple for six years, so she feels like part of their family.

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Neighbor Rich Pina, who also is a retired police sergeant, said he believes his former colleague was targeted.

“When you hear something like that, you always think that there’s more to it than that; that there’s somebody involved that knew the situation. I don’t think he was very well off, but he had some money. He had a nice car, and a beautiful home,” Pina said. “Who knows what all is involved? I don’t think it was random, is what I’m saying.”

Luna said she didn’t know if the retired officer and his wife were specifically targeted, because there had been other recent break-ins in the neighborhood.

“It’s terrible. Just last week I was just telling him there was a break-in … around the corner,” she said.

Luna said the retired officer underwent surgery at Christ. He was out of surgery by early Tuesday morning, and was in critical but stable condition. His wife was at his side at the hospital, and Luna said his two sons from a previous marriage were on their way to Chicago from North Carolina, where they both live.

The couple’s home burned down a few years ago, only to be rebuilt.

Wedryk said his children referred to the retired sergeant and his wife as grandpa and grandma.

“They’re great people. We enjoy coming over to visit them, and they’ve just had a hard time with life,” he said.

A police squad car was parked outside the couple’s home Tuesday morning to stand guard.

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No one was in custody as of late Tuesday morning.