Simplify the following text for a Grade 11 native English-speaking person.
Original: = Train Crashed = On 19 December 2007 , at 2:30 am an overcrowded express train traveling from Karachi to Lahore derailed 2 km ( 1 mile ) south of Mehrabpur killing over 40 people and injuring hundreds more .
Simplified: On 19 December 2007 , at 2:30 am an overcrowded express train traveling from Karachi to Lahore derailed 2 km south of Mehrabpur killing over 40 people and injuring hundreds more .