North India is witnessing an extreme temperature dip, causing dense fog and poor visibility in the region. Amid this, a massive road accident happened near Uttar Pradeshs Unnao this morning (December 27) on the Agra-Lucknow Expressway, leaving one person dead and more than two dozen others injured, the police said.6 vehicles collide with bus amid dense fog on Agra-Lucknow ExpresswayAs many as six vehicles collided with each other in a chain reaction when a double-decker bus lost control due to poor visibility and struck the central divider.VIDEO STORY | UP: Vehicles pile-up in chain collision amid dense fog on Agra-Lucknow Expressway #PTIVideosWatch: https://t.co/D1IHYcGeFBSubscribe to PTIs YouTube channel for in-depth reports, exclusive interviews, and special visual stories that take you beyond the…— Press Trust of India (@PTI_News) December 27, 2023This collision triggered a series of rear-end crashes involving other vehicles.Are there any casualtiesAccording to the UP police, one passenger on the bus succumbed to his injuries at the spot of the incident. At least 24 people sustained serious injuries and were rushed immediately to the Community Health Centre for initial treatment.Among the injured, six individuals in critical condition were referred to the Trauma Center in Lucknow.What was cause of accidentUpon receiving the information, police and emergency were on the scene clearing the wreckage and assisting the wounded people. However, the cause of the accident is still under investigation, said the police.Does heavy fog result in road accidentsA thick blanket of fog descended on large parts of northern India, causing visibility to drop to nearly zero. This dangerous weather condition led to the tragic accident that occurred today.The dense fog severely reduced visibility on the roads, likely contributing to the crash by obscuring obstacles, traffic signals, and other vehicles from view. The extremely poor visibility underscores the heightened risks of driving in hazardous foggy conditions.