(CNN) What seemed like a normal call for two Maryland Heights Fire Protection District firefighter paramedics in St. Louis, Missouri, quickly turned into an unsteady situation unknowingly captured by a stranger.

Jon Stillpass and Shaylor Taetz, who have both been working as paramedics and firefighters for about seven years, had to go to extreme lengths to get a patient to DePaul Hospital in wintry conditions. The two had no idea the event was photographed by Carol Parks, one of the hospital's nurses.

Taetz tells CNN he had picked up an extra shift and was 10 minutes into his coffee when they had to head out on the road for a call concerning a traffic accident.

The two came upon the scene of a metro bus, loaded with just the driver, that had slid on ice and spun around in the opposite direction. The ambulance itself started to slide as they approached, but Stillpass managed to keep the vehicle on the road.

Though Taetz says the driver didn't have any life-threatening injuries, she was shaken up, and it was clear she needed to be taken to the hospital for evaluation.

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