The 16-year-old fell into a nearby river on impact. Her friend, who accompanied her, was also hit and has been admitted to MCH with injuries.
No major injuries have been reported after the train derailed at the Beach Station in Chennai.
The tragedy occurred as Milan, son of Changanassery native Mathai Sebastian, slipped while trying to board a moving train.
The TTE, Ansal (33) hailing from Perumbavoor, was assaulted on the Ernakulam-Howrah Antyodaya Express on Monday evening.
The accident occurred when the Millat Express train from Karachi to Sargodha derailed and fell on the opposite track and collided with Sir Syed Express headed from Rawalpindi to Karachi.
Anujith (27), who saved the lives of hundreds of people back then, set an example even at the time of his untimely death by saving the lives of a few more people.
Thirteen wagons of one of the trains and an engine jumped off the tracks following the collision.
The train, which was carrying metal for construction of double-lane between Haripad and Ambalappuzha, derailed around 2pm near Ambalappuzha railway station.
At least 25 people have been injured in the accident that happened around 7 am between Salagaon and Nergundi stations.
From Delhi, one can hop on to the Samjhauta Express to cross the international border with Pakistan.