Coordinates: The Sonics Arena is a proposed multi-purpose sports arena in Seattle, Washington. It would be built in the SoDo neighborhood of Seattle, and it would host basketball, ice hockey, and concerts. It is part of a larger plan to return the Seattle SuperSonics NBA franchise along with an NHL franchise to the City of Seattle.
The largest arena in the greater Seattle area is the KeyArena. Originally called the Seattle Center Coliseum, the arena opened in 1962. It was remodeled and took its present name in 1995. KeyArena was the home of the Seattle SuperSonics from 1967 to 2008, the duration of the NBA team’s existence in Seattle. The Sonics relocated to Oklahoma City in 2008 and are now known as the Oklahoma City Thunder.
The KeyArena (then named the Seattle Center Coliseum) was the home of the minor professional Western Hockey League Seattle Totems from 1963 to 1975. The KeyArena was later home to the Seattle Thunderbirds of the major junior Western Hockey League from 1977 to 2009. In 2009, the Thunderbirds relocated to the ShoWare Center in nearby Kent. Several professional hockey teams have played in Seattle since 1915. The first was the Seattle Metropolitans, who played in the Seattle Ice Arena from 1915-1924 and became the first American team to win the Stanley Cup in 1917. Other professional hockey teams included the Seattle Eskimos, Seattle Seahawks, Seattle Ironmen, Seattle Bombers, and Seattle Americans.
Other arenas in Seattle include the Alaska Airlines Arena at Hec Edmundson Pavilion, home of the Washington Huskies and Mercer Arena a performing arts venue. Comcast Arena, in Everett, is the home of the IFL’s Everett Raptors and the WHL’s Everett Silvertips.
A key reason given for the Sonics relocation to Oklahoma City was KeyArena’s small size and lack of amenities. Before moving the team, the Sonics ownership proposed that a new arena be built in Renton using $500 million in public funds, but an agreement was not made. In an attempt to keep the Sonics in Seattle, a group of investors led by Microsoft CEO Steve Ballmer promised to pay half of the $300 million needed for a proposed remodel of KeyArena (with Seattle and King County financing the other half), but an agreement was not reached.
On January 21, 2013, the Sacramento Kings were sold to Seattle-native Chris Hansen. These reports were all confirmed by Hansen, the Maloof family, and the NBA.  However, On May 15, 2013, the NBA voted 22-8 to reject the Kings relocation to Seattle. The day after the NBA's decision, the Maloof family reached agreement to sell the Kings to a group led by Silicon Valley tech entrepreneur Vivek Ranadivé for a record NBA franchise valuation of $535 million and the team will stay in Sacramento. 
Despite the failed attempt to move the Kings, Hansen still plans to bring an NBA team back to Seattle, possibly by expansion.
In late 2011, the City of Seattle was approached with a proposal to build a multipurpose arena south of CenturyLink Field and Safeco Field. The total cost of a new arena has been estimated to be $490 million, and the investment group has proposed a direct public investment of up to $200 million, split between the City of Seattle and King County. The investors have agreed to pay any construction shortfalls and for improvements to KeyArena, which could serve as a temporary home for a new NBA team and a new NHL team while the arena is being built.
On February 16, 2012 Seattle Mayor Mike McGinn and King County Executive Dow Constantine announced an agreement with the investors. The Mayor and Executive forwarded a memorandum of understanding was forwarded to the Seattle City Council and the King County Council for further review and approval.
On July 30, 2012, the King County Council approved the draft Memorandum of Understanding that Chris Hansen, Mike McGinn, and Dow Constantine proposed. Earlier that day the Seattle City Council had declared the MOU unacceptable in current form with the intent to renegotiate.
On September 11, 2012, the Seattle City Council reached a tentative agreement with Chris Hansen to build a SoDo basketball/ice hockey arena with revisions including the base rent being reduced from $2 million a year to $1 million, some tax revenue paying for surrounding transportation improvements and KeyArena renovations, and an added 5 year personal guarantee of bond debts from Hansen.
On September 24, 2012, the Seattle City Council approved the proposed SoDo basketball/ice hockey arena.
On October 15, 2012, the King County Council voted unanimously in favor of; while the Seattle City Council voted 7-2 to approve the amended SoDo multipurpose arena proposal.
The primary investor for the project is Chris Hansen. Hansen had a modest upbringing in Seattle’s Rainier Valley neighborhood. He is managing partner of Valiant Capital in San Francisco, where he manages approximately $2.44 billion in public and private investments as of April 2013.
Other investors include Steve Ballmer, CEO of Microsoft; former minor Sonics owner Erik Nordstrom, Executive Vice President and President (Stores) of Nordstrom; and former minor Sonics owner Peter Nordstrom, Executive Vice President and President (Merchandising) of Nordstrom,.
In early April 2012, the Seattle Mariners and Port of Seattle were the first two organizations to publicly oppose the arena proposal. Both sent strongly worded letters to the city and county arguing the location would negatively impact their business. The Mariners argued that “scheduling, traffic and parking challenges that would likely require hundreds of millions of dollars to mitigate.” The Port raised concerns regarding transportation and infrastructure, land use, and asked for an alternative site analysis.
Approximately 6,000 supporters of the arena proposal rallied at Occidental Park on June 14, 2012. At the two hour rally, Chris Hansen, Dow Constantine, and other council members spoke along with former Sonics, Gary Payton, Shawn Kemp, Slick Watts, and Detlef Schrempf.
On July 7, 2012, the Seattle Times wrote an editorial opposing the arena proposal writing, “The glittering offer should be turned down with a resolute ‘no thanks.’” The paper argued that the location would be too detrimental to the business of Port of Seattle and other companies in the industrial area.
On March 13, 2013, Chris Hansen's group released preliminary design renderings of the arena's interior. Configured to support both basketball and ice hockey, the renderings illustrate two unique seating options. Small sideline "pocket" suites would be less than ten rows from the floor. In the upper tier of the arena, three "Sonic Ring" sections would allow for expanded standing room seating that could be opened or closed based on event capacity needs. Each ring would feature approximately 800-900 fixed seats and standing-room capacity for between 700 and 1,500 people.
- Kreamer, Matt (October 15, 2012). "Seattle and King County councils approve Sodo arena deal". Blogs.seattletimes.com. Retrieved 2012-10-28.
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- "Mayor Nickels announces local effort to buy Sonics, renovate KeyArena" (Press release). City of Seattle. May 6, 2008.
- "Maloofs sell Kings to Hansen-led Seattle group". NBA.com. January 21, 2013. Retrieved 2013-03-22.
- "Source: Kings sold to Sacramento group for $535 million". CBS Sports. May 17, 2013. Retrieved 2013-05-19.
- "Source: Seattle’s NBA hopes still high as league warms to expansion". SeattleTimes/com. May 18, 2013. Retrieved 2013-05-19.
- "About the Sonics Arena". SonicsArena.com. Retrieved 2012-07-12.
- "Frequently Asked Questions". SonicsArena.com. Retrieved 2012-07-12.
- "Plans for Seattle NBA arena to be announced Thursday". February 16, 2012.
- Thomas, April (May 16, 2012). "County Executive, Mayor and Chris Hansen reach agreements for arena". Mayor McGinn's Blog. Seattle.gov. Retrieved 2012-07-12.
- Young, Bob (July 30, 2012). "King County Council approves arena proposal". Blogs.seattletimes.com. Retrieved 2012-10-28.
- "Letter from Seattle City Council to Mr. Hansen". Seattle City Council. July 30, 2012. Retrieved 2013-04-27.
- Thompson, Lynn (September 11, 2012). "City Council reaches revised arena deal". The Seattle Times. Retrieved 2012-10-28.
- Thompson, Lynn (September 24, 2012). "Seattle City Council approves new arena". Blogs.seattletimes.com. Retrieved 2012-10-28.
- "Seattle arena deal gets final approval". ESPN. AP. October 15, 2012. Retrieved 2012-10-28.
- Miletich, Steve; Thompson, Lynn (February 15, 2012). "Chris Hansen: Meet the man with the plan for NBA arena". The Seattle Times (Seattle, WA).
- "Some Heavy Hitters Support Seattle Arena". The New York Times (New York, NY). AP. June 23, 2012.
- Q1 2013 losses by Valiant
- Thompson, Lynn; Young, Bob (June 13, 2012). "Ballmer, Nordstroms part of Seattle arena investor group". The Seattle Times (Seattle, WA).
- Thompson, Lynn (April 3, 2012). "Mariners tell city, county: Don't put another sports arena in Sodo". The Seattle Times (Seattle, WA).
- Condotta, Bob (June 14, 2012). "Chris Hansen, ex-Sonics, politicians rally for new arena". The Seattle Times (Seattle, WA).
- Seattle Times Editorial Board (July 7, 2012). "Sodo arena: wrong location, bad plan, no public funds". The Seattle Times (Seattle, WA).
- "SonicsArena.com". March 13, 2013.
- SonicsArena.com, the official website by the private investment group
- King County Council - Arena Portal
- City of Seattle - Arena Portal
- Seattle Times - Latest developments on proposed NBA/NHL arena in Seattle