India, Jan. 26 -- The brutal killing of a 33-year-old professor in Mumbai has left the city in shock. Alok Singh, a Kandivali resident and professor of a prominent college in Mumbai, was stabbed to death on a local train following an argument while getting off at the at the Malad railway station on Saturday.

Singh was a mathematics professor at Narsee Monjee College of Commerce and Economics in Vile Parle. His colleague Sudhirkumar Suryakumar Trivedi, who was an eyewitness to the murder, gave HT a blow-by-blow account of the stabbing.

Singh and Trivedi left the NM College after their classes ended at 5 pm and took an autorickshaw to Andheri railway station. From there, we boarded the Dawn Borivali slow local at around 5:25 pm, Trivedi s...