Overview
- Thane Government Railway Police registered an FIR alleging acts endangering life against a senior section engineer and a section engineer under Bharatiya Nyaya Sanhita Sections 125(a) and 125(b), citing criminal negligence.
 - India Today reports the FIR names Assistant Divisional Engineer Vishal Dolas and Senior Section Engineer Samar Yadav, with allegations of ignored warnings, incomplete welding near track 4, substandard track spacing, and speeds kept above permissible limits.
 - An external technical review cited by investigators pointed to uneven rails, reduced lateral distance between fast lines around the Mumbra curve, and maintenance lapses before the June 9 incident in which four commuters died and several were injured.
 - Central Railway’s internal inquiry concluded there was no technical fault, said trains ran around 72 km/h with adequate clearance, and attributed the trigger to a protruding backpack brushing passengers on the opposite train amid severe overcrowding.
 - Police say the criminal probe is ongoing; earlier an accidental death report was filed, and media reports note conflicting injury counts while investigators describe limited cooperation from some railway staff and efforts to locate the accused.