In 1887, the first mule-drawn streetcar rolled on freshly laid rails down Washington Street and the growth of Phoenix rolled with it, the first city in Arizona to embrace mass transit. As the trolley system grew, so did the city. At its peak in the 20's, rails ran for over thirty miles along city streets carrying over 6.6 million passengers in 1929 alone. It was an integral part of daily life until 1947 when a trolley barn fire destroyed all but 6 cars. Over the next year busses became the backbone of mass transportation in the valley.