Will give the brainlest answer for who answers this question the best
what are some structures that have failed and plz explain why they failed

I will give an example of 2 structures:
1: On May 26, 1896, in Victoria, British Columbia, a streetcar full of 143 people on their way to attend Queen Victoria's birthday, crashed through Point Ellice Bridge into the Upper Harbour. 55 men, women, and children were killed in the accident. The accident occurred because the streetcar was loaded with a much greater weight of passengers than the bridge was designed to support. The city council of Victoria was blamed for this because they had failed to take steps to restrict the traffic on the bridge within safe limits.

2: The collapse of the twin towers on September 11, 2001, was because of the two jet airliners that were hijacked by 10 terrorists associated with al-Queda were flown into the buildings. The south tower collapsed because of its support being crippled by the plane crash. The north tower collapsed from both the second plane and the south tower crashing combined.

Electoral current force mechanical advantage if the wheel and axle is 2 n and the output force is 20 n