British Columbia's large mineral resources also led to a large mining industry. For the most of the 19th century, and well into the 20th century, mining was highly profitable. For the immigrants, once again, this was another opportunity to exploit. Large numbers of immigrants, skilled from their experience mining at home, filled up the labour demands, and quickly, new towns were formed. The city of Nanaimo, for instance, was founded thanks to a large amount of coal found in its harbour. Coal especially, was the fuel of the industry, as coal was required for everything it the time, from ships, to trains, to the heater in everyone's homes.