On 28.09.2020 at 06:55 a.m. from Sofia station to Burgas station, departed fast train (FT) № 3621, in composition of 4 wagons, 16 axles, 162 tons, serviced with electric locomotive №44094.8. The fast train run in Sofia - Karlovo - Tulovo - Karnobat – Burgas direction. The national railway undertaking “BDZ Passenger Services” Ltd., with electric locomotive №44094.8. The locomotive and the transport train crew were employees of “BDZ Passenger Services” Ltd. The train runs daily in the direction Sofia - Karlovo - Dabovo - Karnobat - Burgas and vice versa. The train arrived in Karnobat station at 12:53 p.m., and after a two-minute stay departed at 12:55 p.m. During the movement of the train in Chernograd - Aytos interstation on track № 1, the locomotive crew smelled smoke coming from the engine compartment. The locomotive driver undertook a quick stop, and the train stopped at 13:07 p.m. , evident from the records of the locomotive's recording device. The locomotive driver activated the fire protection system, however the fire protection system did not start. The assistant locomotive driver and the locomotive driver tried to put out the fire with the portable fire extinguishers of the locomotive, but they failed due to the thick smoke. The locomotive driver called the national telephone number 112 to ask assistance from the fire services. The train was moving at a speed of 120 km/h, with a permissible speed of 130 km/h. During the train's movement on the route from Sofia station to Chernograd station the operation of the locomotive was accident-free.
As a result, from the fire in electric locomotive № 44094.8, no staff and passengers on the train were injured; damages were caused to the electric locomotive, and no damages to the railway infrastructure.