Final answer:
Locked emergency exits were a major factor in the loss of lives at the Coconut Grove nightclub fire in 1942, similar to the Triangle Shirtwaist Factory fire where locked doors also impeded escape.
Step-by-step explanation:
A major factor in the loss of lives at the Coconut Grove nightclub fire in 1942 was C) Locked emergency exits. This tragic event echoes the circumstances of the earlier Triangle Shirtwaist Factory fire in 1911, where locked doors also significantly contributed to the high death toll. In both disasters, the inability of victims to escape due to locked exits drastically increased the number of casualties.