There are painted white cinder blocks that separate the Duke locker room from the outside hallway in the depths of the Smith Center. Mike Krzyzewski’s voice penetrated through them as he addressed his Blue Devils after they lost 74-66 at North Carolina, letting a second-half lead slip away as they failed to make shots and answer any of UNC’s momentum.

The fact that Krzyzewski was voicing his displeasure – loudly – isn’t out of the ordinary.

“Yeah,” Rasheed Sulaimon said, with no hesitation, when asked if that was normal.

“It’s just the way we lost,” Tyler Thornton said. “We didn’t fight the way we should have in the second half. That’s on us.”

And that, an issue that hadn’t come up in other losses, is what had a more subdued Krzyzewski frustrated as he addressed the media about 10 minutes later.

“We looked tired, or, I don’t know, we didn’t have life,” he said. “No matter what we did in a timeout, we just didn’t have that spark, that spark, that anger, the emotion, the,” he paused, “thing you have to have to match what their crowd, their team is doing. You have to try to counter that. I just felt we didn’t have a life that we needed to have.

“I’m disappointed that we couldn’t play better in the second half.”

The No. 5 Blue Devils (21-6, 10-4 ACC) played well in the first half, limiting point guard Marcus Paige to zero points and 0-of-2 shooting, thanks to the efforts of Sulaimon, Thornton and Quinn Cook. Duke also collapsed well on UNC’s post players, rendering Brice Johnson and Kennedy Meeks, especially, irrelevant.

It was Duke, not UNC, that found success in the paint in the opening 20 minutes, thanks to a flurry of drives that led to 26 points in the paint, compared with 14 for UNC.

The Blue Devils even built an 11-point lead in the opening minutes of the second half, thanks to a drive from Parker that put them ahead 51-40. And then Duke didn’t score another field goal for nearly nine minutes.

By the time Cook finally put one in high off the glass with 6:26 left in the game, Duke was clinging to a four-point lead. That was gone for good about three minutes later.

“What killed us was shot selection, finishes and on defense, most importantly,” said Parker, who became the first Duke freshman since Kyle Singler in 2008 to record a double-double against the Tar Heels.

“We had some good looks,” Krzyzewski said. “When you have the layups, you’ve got to put those things in. You’ve got to counter somehow. Sometimes good offense can make up for the fact that you don’t have that juice.

“Our team has played so well. We are in a crazy time, but the emotion of this game and the respect that you have for your opponent and being in this game should carry you through something like that. I thought we played young. Young, and we didn’t have the life, we couldn’t get that. There was something missing. Carolina wasn’t.”