Connors Company (Connors) (plaintiff) owned a barge called the Anna C. The barge carried a load of flour owned by the United States (plaintiff). Connors hired Carroll Towing Co. (Carroll) to tow the barge with its tug boat. Carroll chartered its tug boat to Grace Line (Grace) (defendant), another tug company. On January 4, 1944, Connors’ barge was docked at Pier 51 on the North River. Connors’ employee who was tasked with watching the barge had gone ashore. Carroll’s tug boat attempted a tricky move of the Anna C to another dock, but this maneuver failed and ultimately set loose all other boats at the dock. The boats floated down the river and the Anna C sank. Connors brought suit against Carroll and Grace for damages from the loss of the boat, and the United States brought suit against Carroll for the loss of the flour. At trial, Carroll and Grace defended on the ground that Connors was contributorily negligent because its employee was absent from the barge at the time of the incident. The trial judge found that Carroll, but not Grace was responsible for one-half the damage to the Anna C and for the entire loss of the flour. The parties appealed.