The 'Stay' duo were preparing to perform at the Indiana State Fair in August, when high winds caused the stage to cave in. Dozens of fans were injured in addition to the seven who lost their lives in the accident.
Nettles described the stage collapse as a "tragedy" during an interview with Good Morning America's Robin Roberts on Tuesday.
"I think any sort of crisis can test our faith, and push us to our limits. There will always be a before that happened, and an after that happened," Nettles said.
The singer went on to say: "We are forever connected to those people, because of the evening that we shared, and the moment that we shared, and the tragedy that we shared."
Last month, Sugarland toured the site of the collapse, where much of the band's equipment is still buried in rubble.
Reflecting on the tragedy, Bush said: "Your brain didn't know what to do with it. There was just dust everywhere. Everything shook. It was like an earthquake."
Sugarland returned to Indiana on October 28 to play a free concert as a tribute to those who were killed.
They have also urged their fans to donate to the Indiana State Fair Remembrance Fund in memory of the victims.
Watch Sugarland discuss the tragic stage collapse below: