Retired NYPD Officer With 9/11-Related Illness Kills Self

An NYPD officer who worked 40 days straight at Ground Zero following the 9/11 terrorist attacks killed himself this week amid an ongoing battle with lung disease.

Retired Capt. Douglas Greenwood died after he shot himself in the chest at the entrance of Greenlawn Park near his Suffolk County home Tuesday night, according to The New York Post.

The 61-year-old, who began a second career as owner of the famous Bleecker Street Pizza after 26 years with the NYPD, often struggled with thoughts of suicide as he struggled withe his illness. For the last 10 years, Greenwood slept with an oxygen tank and underwent multiple surgeries and procedures.

"He talked about shooting himself as an inevitable thing," longtime friend and photographer Kevin McCormick told the newspaper. "He said, 'When there's no more quality of life, I'm going to do it."

As captain of the Manhattan South Task Force, he was in charge of all the NYPD boots on the ground.

"He'd be commanding the scene, but he also did grunt work -- everybody pitched in," Ralph Friedman, an author, TV personality and retired detective who was Greenwood's friend for 25 years, said. "Everyone was sifting through the scene for bodies, body parts."

His brother Gregory said he never married or had kids.

"He was married to the NYPD and pizza."