Final answer:
The 3rd due engine company on a box alarm has responsibilities such as establishing water supply, stretching hoselines, and assisting in search and rescue.
Step-by-step explanation:
The responsibilities of the 3rd due engine company on a box alarm vary depending on the specific procedures of the fire department, but there are some common tasks they typically handle. Some responsibilities include establishing a water supply, stretching hoselines, and assisting with search and rescue operations. They also ensure that the fire is extinguished, overhaul the area, and assist with salvage and overhaul.