Complex sentence: San Francisco's City Engineer estimated the cost at $100 million, which would be $2.12 Billion today and impractical for the time, and fielded the question to bridge engineers of whether it could be built for less.
Split into simpler sentences: San Francisco's City Engineer estimated the cost at $100 million, which would be $2.12 billion today, and impractical for the time. He fielded the question to bridge engineers of whether it could be built for less.