Transportation infrastructures are primordial components of the economy, which encompasses the mobility of people, goods and information. Railways play a major role in the global transportation system due its high capacity and environmental efficiency concerning greenhouse gas emission when compared to roads. However, the literature is still incipient regarding the harmful effects that railroads can cause on wildlife. Despite roads and railways have distinct physical structures, much of the scientific knowledge obtained on roads are extrapolated to railways, what may be a risky strategy. For example, railroad tracks may pose a physical barrier to small animals in a different way than roads. In this context, and in order to understand and propose measures that make railroads even more environmentally friendly, it is important to understand how small animals interact with railroads. Identifying the causes of small animal mortality on railroads is key to inform better mitigation. In this work we evaluated episodes of interaction between the small fauna and the Estrada de Ferro Carajás (EFC), an 892 km long railroad located in the Brazilian Amazon. The EFC was monitored on foot for 4 years, as requested by the Brazilian Environmental Agency as part of the evaluation process for rail lane duplication. Empirical field observations, as well as video recordings and photographs, were gathered and analyzed in order to understand circumstances in which small animals died on the railroad. We found that the rail tracks actually act as a physical barrier structure, especially for low-jumping amphibians and tarantulas. Carcasses of these animals were frequently found intact and desiccated. We hypothesize that these animals, predominantly nocturnal, may die from the intense heat emanated from the railway structures during daytime. Moreover, it was reported that the carcasses of some animals, such as lizards and amphibians, had everted inner organs on their mouths, which could be the result of barotrauma. Given this fact, we assumed that the air displaced by the moving train may cause an internal blowout in the animals. Since the rail tracks act as a physical barrier, small animals keep trying to cross to the other side or get trapped between tracks, increasing the chances of mortality from other than being killed by the train. We believe that the implementation of simple crossing structures under the railway tracks could assist animals' crossings and consequently avoid part of the mortality on the railroad. Our inferences about mortality causes on railroads are based on the interpretation of our empirical observations, but more in-depth studies are needed to test hypothesis concerning mortality causes. The findings of this work bring new information to railroad ecology and help to disrupt the myth that railroads kill animals in the same way as roads.