Two friends who met decades ago wound up working in two schools touched by mass shooting

Yvonne Cech worked at Sandy Hook Elementary in Newtown, Connecticut, when a gunman killed 20 children and six adults. Diana Haneski became a librarian at Marjory Stoneman Douglas High School in Parkland, Florida, where a gunman killed 17 people.

When the school shooting began in Parkland, Florida, Haneski immediately thought of all the things her friend Cech had told her over the years.

In an interview with CNN's Anderson Cooper on "AC360," Haneski said Cech had told her she needed to "make sure you have your keys on your person, your phone, your walkie-talkie. Those things were very important."

"I was trying to be ready, but I didn't think it would be getting ready for this," Haneski said.

Cech told Cooper that she was in "absolute disbelief" over the Parkland school shooting.

"It made me furious," she said. "It made me angry that this had to happen again. So many people have said to me in the last few days, 'What are the chances? What are the odds that you would have gone through this and that your close friend would have gone through the same thing?' And I have to say that I think the odds are just getting greater and greater, until we do something to stop this problem of gun violence.

When Cech heard about the shooting in Florida, she said she felt the need to travel to Stoneman Douglas High School.

"I just had to go and be with her and make myself available in case any teachers wanted to talk about what they had just gone through," Cech said.

Haneski expressed how happy she was to see her friend, whom she had met when they were both working at a radio station in Connecticut.

"I couldn't speak," she said. "I was more frozen those first few days. I didn't want to eat. It was scaring me, so of course I went through the counseling, which was very helpful. ... But having Yvonne there was wonderful because she arrived and we went right to Joaquin's service."

The Stoneman Douglas librarian added that Cech was able to speak about her Sandy Hook experience at a community event with parents and students.

"They were coming up to me later, (asking) 'Can you give me what she wrote, what she read?'" she said. "Little things that people were going, 'Oh my God, I feel that way.' Oh, she's helping me. I really needed this. It was amazing that she came to help us."

Cech has said that the Parkland shooting is a teachable moment, because the students are asking the adults to solve the problem of gun violence.

"The students at Sandy Hook school where too young to be able to articulate their fears and their hopes for solving this issue," Cech said. But the students at Stoneman Douglas are not letting go of this. They are strong and they are loud and they need to be loud. Because we have had too many of these situations happen. We should have fixed this problem 20 years ago after Columbine, and we didn't."