Three of the men who have been hailed as heroes after detaining the Sydney CBD attacker have described the moment they caught him.

The attacker, who Ben Fordham is choosing not to name, allegedly stabbed 24-year-old Michaela Dunn to death and severely injured another.

NSW Police Commissioner Mick Fuller has labelled the men who held him down with milk crates and a chair as “heroes” but they say they were just doing what felt natural.

Lee Cuthbert, Paul O’Shaughnessy and his brother Luke O’Shaughnessy joined Ben Fordham in the studio 24 hours after the major incident, revealing they first saw the attacker from the window of their fourth-floor office.

Watch them describe the moment they confronted the attacker

Paul tells Ben they don’t regard themselves as heroes but is proud of what they did.

“I’m really proud that we all instinctively went downstairs to help.

“If that was to happen again mate, hand on my heart, we’d do it again.”

Luke says the moment they detained the attacker was confronting.

“He wasn’t with it.

“I looked at him and thought how has this guy caused so much damage, damage to the extent that I didn’t even know yet… but I knew from what I could see… he’s caused something that’s catastrophic.”

Click PLAY to hear the full interview

Firefighters who helped subdue the attacker are also being praised for their efforts.

The crew happened to be stuck in traffic as the attack unfolded and sprung into action.

Fire and Rescue NSW Assistant Commissioner Paul McGuiggan tells Ben Fordham they handled the situation calmly and courageously and are “going well”.

“I think the adrenaline is starting to seep out of the body and they’re becoming much more aware of the events that unfolded yesterday.”

Click PLAY below to hear the full interview

Ben provided extensive coverage during the CBD attack on Tuesday.

Click PLAY to hear the gripping moments broadcast on air