Final answer:
The signal word in the passage indicates a significant problem that needs urgent attention, reflecting the use of signal words to organize text and alert the reader to important narrative changes.
Step-by-step explanation:
The authors used a signal word in the passage to signal a problem. The phrase 'this was really bad' indicates that there is a significant issue that the Apollo 13 crew needs to address quickly.
Signal words are used in writing to indicate something important to the reader, helping to organize the text and clue them into changes in the narrative, such as the introduction of a problem, a solution, or a resolution.
In this case, the signal word is used to set the tone of urgency and the critical nature of the situation faced by the characters.