Cannatella's officers and their families have paid a heavy price over the last two weeks.
Officer Bryant Louis watched helplessly as he passed by his family waving for help from a rooftop.
"We had several people stuck on roofs of homes at the time, and I couldn't possibly ask for anyone to bypass any survivor in order to get a relative. I just couldn't do it," Louis recalled. "So my mother and my family ended up staying a day and a half on the roof before I was able to get two of my co-workers to assist me and rescue them."
Lesley St. Germain and Bridget, her 2-year-old daughter, went to Baton Rouge. Her husband, a lieutenant with the New Orleans Police Department, ignored their pleas to join them.
"Please just leave. Just take off out of there, and he didn't want too." Leslie remembers. "He said too many people depend on me."
This past week, Lieutenant Terry St. Germain took a break to check on his family's home. He found that it had been looted.
"My wife's jewelry is missing. I brought it back here last night thinking it was safe, and I was wrong," said St. Germain.
"He called me on the phone, and he said everything is gone in our house," Leslie added. "He was crying and weeping, and he just pretty much couldn't handle it."
"I'm so frustrated. I can't stand it. You know why I'm frustrated?" St. Germain asked. "Because I'm very, very angry this happened to me. Because I'm protecting these people and working around the clock, and all my brother and sister officers lost their whole house, and I can't even hardly be mad about this because I still have my house. So I guess I'm lucky I got looted."
For others, the aftermath of Hurricane Katrina has been far too much.
Sgt. Paul Accardo, a public information officer, used his service revolver to kill himself.
"He was worried about his family, about getting in touch with them, and he was very distraught because he felt like he had let them down because he couldn't find them," Leslie explained.
It turns out Accardo's family was fine. Funeral services for the sergeant and another officer, who also took his own life, were held this week.
"To me, they died in the line of duty. They died of injuries caused to their psychological being from this storm," says Cannatella. "That they were told you have to perform, you have to protect, and you have to serve, and they did."
As for the captain himself, "You know, my wife asked me the other day, she said, 'Why do you still do this? Why?' And I said, 'Well, you get up every day, and you go to work with heroes.' Not everybody can say that."
ABC News' Maddy Sauer, Rhonda Schwartz, and Vic Walter contributed to this report.