air-conditioning plant, the largest in Australia at the time, supplying over of air per minute, using the innovative idea of harnessing the harbour water to create a water-cooled heat pump system that is still in operation today. Opening The Sydney Opera House was formally opened by Queen Elizabeth II, on 20 October 1973. A large crowd attended. Utzon was not invited to the ceremony, nor was his name mentioned. The opening was televised and included fireworks and a performance of Beethoven's Symphony No. 9. Reconciliation with Utzon; building refurbishment In the late 1990s, the Sydney Opera House Trust resumed communication with Utzon in an attempt to effect a reconciliation and to secure his involvement in future changes to the building. In 1999, he was appointed by the trust as a design consultant for future work. In 2004, the first interior space rebuilt to an Utzon design was opened and renamed "The Utzon Room" in his honour. It contains an original Utzon tapestry (14.00 x 3.70 metres) called Homage to Carl Philipp Emanuel Bach. In April 2007, he proposed a major reconstruction of the Opera Theatre, as it was then known. Utzon died on 29 November 2008. A state memorial service, attended by Utzon's son Jan and daughter Lin, was held in the Concert Hall on 25 March 2009 featuring performances, readings and recollections from prominent figures in the Australian performing arts scene. Refurbished Western Foyer and accessibility improvements were commissioned on 17 November 2009, the largest building project completed since Utzon was re-engaged in 1999. Designed by Utzon and his son Jan, the project provided improved ticketing, toilet and cloaking facilities. New escalators and a public lift enabled enhanced access for the disabled and families with prams. The prominent paralympian athlete Louise Sauvage was announced as the building's "accessibility ambassador" to advise on further improvements to aid people with disabilities. In 2013, a 60 metre long artwork by artist Reg Mombassa was unveiled at the Sydney Opera House. The Gumscape, Road and Creatures triptych was commissioned by the Sydney Opera House to cover the scaffolding concealing refurbishment building work. On 29 March 2016, an original 1959 tapestry by Le Corbusier (2.18 x 3.55 metres), commissioned by Utzon to be hung in the Sydney Opera House and called Les Dés Sont Jetés (The Dice Are Cast), was finally unveiled in situ after being owned by the Utzon family and held at