A Bell 407 GX aircraft hovers overhead as the crew takes aerial photos of 1,000 residents walking in formation at Liangjiang Square in Yunyang county, Southwest China's Chongqing municipality on Sept 12, 2015. (Source: www.news.cn)

　　CHONGQING, Sept. 13 (Xinhua) -- A helicopter crash in southwest China's Chongqing Municipality on Sunday killed four people, local authorities said.

　　The crash happened at around 1 p.m. when the Bell 407 GX aircraft lost contact with ground control, after departing from Wanzhou District to Liangping County.

　　Rescuers found the debris of the helicopter and all four victims at around 6:30 p.m. in Hucao Village of Liangping County.

　　Cause of the air crash is under investigation.