SW China colliery blast kills 3, injures 4

 　　GUIYANG, Feb. 19 (Xinhua) -- Three people were killed and four others injured, including three who were seriously injured, in a coal mine blast in southwest China's Guizhou Province, local authorities said Tuesday.

　　The blast occurred around 5:25 p.m. at the Kaifa coal mine in Jinsha County, when officers from a local police station and coal mine workers were destroying expired explosives, sources with the county government said.

　　The three who sustained serious injuries have been sent to a local hospital.

　　An investigation¹ into the cause of the blast is underway.

1 investigation   

n.调查，调查研究

参考例句：

• In an investigation,a new fact became known, which told against him.在调查中新发现了一件对他不利的事实。
• He drew the conclusion by building on his own investigation.他根据自己的调查研究作出结论。