Improper fastening of the railway track is blamed for the derailment of the Chandigarh-Dibrugarh Express in Uttar Pradesh, leading to four deaths and multiple injuries. Investigations found cloth pieces and missing clips used to secure the track, with disagreements within the team about the findings and responsibility. The findings were deemed premature by a Railway spokesperson, while the engineering department was held accountable for the accident due to ineffective fastening. Further investigations by the Commissioner of Railway Safety are ongoing to delve into technical specifics to understand the full scope of the incident.