LAKE CITY, Fla. -

Working behind the counter at the Blue Roof Grill, Betty said she sees a lot of customers, many who work at the Columbia Correctional Institution.

But she very clearly remembers Sgt. Ruben Thomas, a corrections officer who investigators said was killed late Sunday night by an inmate. Betty said she saw Thomas in the restaurant several times a week.

"Very honest, very outgoing, very fun, full of life, loved his family, loved his fiancee, and was ready to work every day," she said.

Betty said Monday was a hard day because so many staff and customers weren't taking the news easy.

"It's really sad to hear anything like this happen, and we feel very bad for his family," she said.

Ruben Thomas "It's bad enough when an officer goes down in the street, but to be there in a confined place where these people are supposed to be held responsible, and they come up and they can kill somebody in there, that's not right," customer Carol Semas said.

Semas has lived in Lake City for years and can't believe this kind of tragedy would even happen in the community.

Other residents said Thomas was known as Little Ruben, and everyone who knew him knew he was excited about becoming a father again. He was expecting his second child.

"It's sad. That's a dangerous job they're doing, and they have to remember how dangerous that job can be," resident Willie Mae Williams said.

"I've been in situations where I've been at work and, you know, people get stabbed, and it goes with the territory," former corrections officer Wilbert Austin said of the dangers of the job. "When you go to work, kiss your family, pray for them, because you never know what's going to happen. Any course of things could happen any time at any day."

Austin said even though every officer goes through training, there are some situations they just can't anticipate.

"When I worked at the prison, they had this thing called lock-in-socks," Austin said. "They take combination locks from their lockers, put them in their socks and attack people with them. It's very dangerous."

The institution has a maximum capacity of just more than 1,400 inmates. The state said it holds all levels of inmates there, except those on death row.

Channel 4 crime analyst Ken Jefferson also used to be a corrections officer and said relying on training is key.

"In this case, sounds like the inmate -- sounds as though he lured the corrections sergeant down to talk to him, but in essence he ambushed him. He brought him down there specifically to attack him," Jefferson said. "But it's a very dangerous situation you're in on a daily basis. You've always got to rely on your backup. You've always got to rely on your training, and you've always got to rely on your instinct."

The state prison system is dealing with a budget shortfall of $79 million. Austin said his concern is that in the long run, this kind of a shortfall could end up hurting these institutions when it comes to safety.

"You've got less people that's probably going to be working, so you're dealing with a smaller workforce," Austin said.

For residents like Williams, Thomas' death is not just a reminder of how many men and women risk their lives working at the institution, but it's also a reminder that this community won't be able to move forward unless it is there for each other.

"We do need to come together," Williams said.