1930s, the war years of the 1940s cemented Reno as the place to play for two decades. Beginning in the 1950s, the need for economic diversification beyond gaming fueled a movement for more lenient business taxation. At 1:03 pm, on February 5, 1957, two explosions, caused by natural gas leaking into the maze of pipes and ditches under the city, and an ensuing fire, destroyed five buildings in the vicinity of Sierra and First Streets along the Truckee River. The disaster killed two people and injured 49. The first explosion hit under the block of shops on the west side of Sierra Street (now the site of the Century Riverside), the second, across Sierra Street, now the site of the Palladio. The presence of a main east–west rail line, the emerging interstate highway system, favorable state tax climate, and relatively inexpensive land created good conditions for warehousing and distribution of goods. In the 1980s, Indian gaming rules were relaxed, and starting in 2000, Californian Native casinos began to cut into Reno casino revenues. Major new construction projects have been completed in the Reno and Sparks areas. A few new luxury communities were built in Truckee, California, about west of Reno on Interstate 80. Reno also is an outdoor recreation destination, due to its proximity to the Sierra Nevada, Lake Tahoe, and numerous ski resorts in the region. In 2018, the city officially changed its flag after a local contest was held. In recent years, the Reno metro area − spurred by large-scale investments from Greater Seattle and San Francisco Bay Area companies such as Amazon, Tesla, Panasonic, Microsoft, Apple, and Google − has become a new major technology center in the United States. Geography Environmental considerations Wetlands are an important part of the Reno/Tahoe area. They act as a natural filter for the solids that come out of the water treatment plant. Plant roots absorb nutrients from the water and naturally filter it. Wetlands are home to over 75% of the species in the Great Basin. However, the area's wetlands are at risk of being destroyed due to development around the city. While developers build on top of the wetlands they fill them with soil, destroying the habitat they create for the plants and animals. Washoe County has devised a plan that will help protect these ecosystems: mitigation. In the future, when developers try to build over a wetland, they