In August 2016 a fire occurred in the Gleinalmtunnel which had a serious impact on the tunnel structure as well as on the entire traffic situation of the detour. On the detour the motorway operator (Asfinag) ordered the dismantling of all constructions sites to ensure a smooth flow of traffic. The initiator of the fire was a motor-coach, which was converted into a camping bus. The bus caught fire in the engine compartment after entering the Gleinalmtunnel. The driver stopped the bus in an emergency bay and tried to extinguish the fire with a hand-held fire extinguisher. However, this attempt was not successful and the bus burned completely. At this fire event, fortunately nobody was injured but the structure was damaged substantially. The fire was fought by the “Tunnelbasiseinheiten” north and south and their equipment. Because of the enormous heat, the stability of the ceiling of the emergency bay and the concrete intermediate ceiling were weakened in such way that the tunnel had to be closed for three weeks and reconstruction was necessary. Furthermore, in this area damaged electric devices had to be uninstalled and renewed. During reconstruction the main focus was the safety of the miners and the subsequent tunnel users. However, also the lack of toll played a major role which led to rapid planning and reconstruction. With reference to the plans of the imminent overhaul of the west tube of the Gleinalmtunnel (2017) it was decided to completely fill the breakdown bay with concrete in order to eliminate the static problem of the almost forty year old anchor beam. The testing of the concrete and reinforcement samples that were taken showed that the part of the intermediate ceiling, which had massive spalling of the concrete due to the heat, had to be cut out and renewed. In the area of the breakdown bay the intermediate ceiling was anchored with 60 rock bolts (GEWI® mechanical anchors and SN anchors). An additional challenge for the designer as well as the construction company was if possible not to be dependent on delivery times. This was only achievable because of the good cooperation between the planer and the construction company of the new tube of the Gleinalmtunnel. Materials that were not available on site where delivered from nearby construction sites or were produced single-handedly. The suppliers were very helpful which meant that there was no standstill on the construction site. However, there were other challenges like the availability of personnel and heavy machinery like wheel loaders and drill jumbos and the adaption for drilling works from the driving space to the surrounding rock. The coordination of the work, the compliance with standards and guidelines as well as the consideration of safety relevant aspects were the key topics of the reconstruction. In the last chapter of the thesis the latest state-of-the-art technology for hazard detection, fire fighting, emergency call devices and escape routes as well as structural measures for an increased fire safety in underground structures are discussed.