The introduction sets the stage for discussing fascinating stories of construction projects that encountered unexpected problems.

• The introduction emphasizes the unseen challenges in construction and the issues that can arise unexpectedly.

San Francisco's Millennium Tower is sinking and tilting due to inadequate foundational support, leading to significant engineering efforts to correct it.

• The 197-meter-tall Millennium Tower has sunk over 45 cm and leans 60 cm to the west and 20 cm to the north.
• Efforts to correct the tilt include installing new piles, but the tower continues to tilt at an increasing rate.
• The foundation issues were underestimated, and nearby construction work may have exacerbated the problem.
• Legal battles ensue as the cost to fix the lean could exceed $100 million.

Golden Finance 117 in Tianjin, China, remains unfinished due to financial difficulties and market conditions, becoming the tallest 'ghost scraper.'

• The building was planned as a 597-meter-tall skyscraper and would have been the fifth tallest in the world.
• Construction halted due to the financial crisis and market volatility, with the project now standing incomplete.

New York City's skyscraper at 161 Maiden Lane is leaning due to alleged foundation shortcuts, leading to halted construction and legal disputes.

• The skyscraper is leaning 8 cm to the north and is abandoned before completion.
• Allegations suggest foundation issues due to soil treatment rather than using piles.
• Legal battles between the contractor and developer are ongoing, with no clear remedy in sight.

California's high-speed rail project faces delays, budget overruns, and political hurdles, casting doubt on the project's completion.

• The project aims to connect Southern California with San Francisco but is behind schedule and over budget.
• Originally estimated at $33 billion, the project's cost has now escalated to over $100 billion.
• Funding issues and skepticism about the project's viability are significant challenges to its completion.