Gerry Morrell, with the Lafayette Historical Society and the mitigation group, said that the north pillar collapsed because it had no foundation, so when it was relocated the unsteady base caused the pillar to topple over.

Source: https://www.coloradohometownweekly.com/2023/01/15/erie-lafayette-area-residents-discuss-mitigation-possible-move-for-wwi-memorial-pillars/

In the exciting stunt, Ethan Hunt and his assailants fight inside a train hurtling off the tracks and over a cliff, with Hunt dangling to his doom as the last car threatens to topple over the side.

Source: https://screenrant.com/mission-impossible-dead-reckoning-part-1-stunts-ranked/