Answer:
1 they could face distraction.
2 they could also face construction\planning mistakes.
3 last but not the least, carelessness.
Step-by-step explanation:
1 Distraction from neighboring animals like crocodiles , alligator, bears and so on.
2 Mistakes. How? Well, if the technician in charge of making the plans mistakenly uses a wrong measurement or angle as the case may be, this could lead to a high level disaster.
3 How? Well, I noticed that there is a river by the side of the railway. If one of the engineers wasn't careful and fell, it could cause low or no concentration as fear is present.
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