The issues related to modeling the cascade development of emergency situations, in particular, fires in parking lots, are considered. It is shown that when a car catches fire, both it and neighboring cars can suffer. It is shown that the damage from the fire can be of a cascading nature and will be determined by how soon the extinguishing and restoration of the normal functioning of the parking lot will begin – how quickly repair and restoration work will be carried out. The assessment of the probabilities of the parking lot conditions «normal functioning – fires – extinguishing – restoration» was carried out in two ways – using the methods of the theory of Markov processes (with discrete time) and adapted queuing systems (with continuous time). Analytical expressions are obtained and examples and comparison of the results of estimating the probabilities of states obtained in two ways are given.