Theory:

     As she was about to exit herself, she noticed three children who were left in the flight. They needed her help in escaping. As the brave-heart rescued the kids, she was hit by the bullets fired by one of the terrorists. The wounds inflicted were fatal, and Neerja eventually succumbed to them. By a cruel twist of fate, this heroic young girl passed away.
Explanation:
 
Neerja helped the passengers to escape from the dangerous situation of the plane. At last, when she was about to leave, She found three children left on the flight.
 
Kids inside flight.jpg
Kids inside flight
 
Neerja was shocked to notice those three kids left alone in that dangerous situation. Those three kids required the help of someone to get them saved from the terrorist attack. The selfless, divine being did not care about her life. She took the effort to save the children from the terrorist's attack.
 
A brave woman Neerja.jpg
Neerja - A brave woman

While rescuing the children from the terrorists, the brave-heart was hit by one of the terrorists' bullets and wounded. The wounds were severe, and Neerja finally died as a result of them. This brave young girl had died in a cruel twist of fate.
 
Meaning of difficult words:
 
S.No
Words
Meaning
1.
Exit
An act of leaving a place
2.
Rescue
To save someone from a dangerous situation
3.
Wound
A serious injury in which your skin is cut or damaged
4.
InflictTo cause something unpleasant
5.
FatalCausing death or bad result
6.
Eventually Finally or at the end, after a long period
7.
Succumb To die from the effect of an injury
8.
FateThings happen to someone, especially unpleasant
Reference:
State Council of Educational Research and Training (2019). Term-3 English Standard-7. A Story of Self Sacrifice and Bravery (pp. 105-111). Published by the Tamil Nadu Textbook and Educational Services Corporation.