Mary and Carrie and baby Grace and Ma had all had scarlet fever. The Nelsons across the creek had had it too, so there had been no one to help Pa and Laura. Laura Ingalls Wilder
The summer of 1830 I... blasted the tunnel through the rock to take water from the dam above the falls for the mill... In 1831 we lowered the tunnel four feet, and built a new dam across the creek. Ezra Cornell