The Second Industrial Revolution absolutely changed the landscape of the modern urban environment in multiple ways, but most importantly through the use of electricity, in communication, and transportation.
Electricity begins to be used in simple machines in the Second Industrial Revolution, and with increased scientific knowledge and inventions, the use of electricity in the city becomes more widespread. Many of these inventions improved home life for the city dwellers, and use of electric lighting on city streets decreased crime.
Many break-throughs in communication occur as well, including the telegraph, telephone, and eventually radio waves, allowing people to communicate over long distances.
Transportation--this is the most revolutionary of the three I mentioned. Not only does transportation improvements such as steam engines, trains, steamboats (from the First Industirial Revolution) effectively shrink the urban world, but in the Second Industrial Revolution, combustion engines are invented--giving people even more mobility by the use of personal automobiles, buses, and eventually even planes. For city folk, the prospect of car ownership allowed them the freedom to withdraw from city life and the urban environment and move into the suburb to commute to work.