A survey shows that the September eleventh, 2001 terrorist attack was the most shocking TV moment in the past five decades.

In the survey, research company Nielsen asked 12-thousand Americans about the most powerful, unforgettable TV experience they could recall. The largest number of respondents cited reports following the September eleventh terrorist attacks on the World Trade Center and the Pentagon.

Other unforgettable moments mentioned include Hurricane Katrina in 2005, murder charges against former star football player O. J. Simpson in 1995, and the explosion of the space shuttle “Challenger” in 1986.

The research company said the top 20 answers were news reports, indicating that news is the most influential TV experience.