A collision of high-speed trains on 23 July 2011 in Zhejiang province killed 40 and injured 195, raising concerns about operational safety. A credit crunch later that year slowed the construction of new lines. In July 2011, top train speeds were lowered to . But by 2012, the high-speed rail boom had renewed with new lines and new rolling stock by domestic producers that had indigenized foreign technology. On 26 December 2012, China opened the Beijing–Guangzhou–Shenzhen–Hong Kong high-speed railway, the world's longest high-speed rail line, which runs from Beijing West railway station to Shenzhen North Railway Station.