"What-" Her voice died as if breath had failed her.

He tried to scream, but his breath failed him.

But after a while they forgot about him, and his breath failed without anybody's noticing.

His breath failed him as if he had been struck in the chest with a sledgehammer.

Do not come down; I shall get strength again, Only my breath fails.

Her voice faded and breath all but failed her.

But Jacopo would have stopped in any case, because his breath was failing.

His strength gave out, breath failed him, and he was obliged to stop.

"Fetch her," he was still saying, a catechism to be repeated until his breath failed.

Then time alone becomes the tormentor; in the end her breath will fail.