HANOI, Jan. 15 (Xinhua) -- Two workers died after being overcome by toxic gas in an underground manhole in Vietnam's southern hub Ho Chi Minh City on Thursday, Vietnam News Agency reported.
The incident occurred at around noon when two male workers opened a manhole for inspection. One worker climbed down using a ladder but was overcome by gas and cried for help.
His colleague descended to rescue him but was also affected and unable to climb back up.
Police and rescue forces used oxygen masks, specialized ropes and ventilation equipment to retrieve the victims.
The cause of the incident is under investigation. ■
