The road leading to Thu Thiem Tunnel in Ho Chi Minh City caught fire during construction Friday morning due to a problematic air compressor.
No causalities were caused and damage to the machine was around VND5 million (US$264), according to officials. The compressor was used to install sections of the tunnel, Vietnam's first underwater passageway.
The fire spread to the tunnel but workers managed to contain it using wet cloth and fire extinguishers before six fire trucks were sent in to extinguish the blaze half an hour later.
Construction at the road has returned to normal, officials said.
HCMC authorities are investigating the cause of the fire.
The 1.5 kilometer tunnel under the Saigon River is the main part of the East West Highway Project. The underwater section comprises four parts, each of which is 92 meters long and weighs more than 27,000 tons. The final section was successfully installed Saturday last week.
Construction started in 2005 and is expected to be completed in August this year. The three-lane tunnel linking HCMC's Districts 1 and 2 is scheduled to open to traffic next year, allowing vehicles to travel at 60 kilometers per hour.
Last month, 241 wet spots and 19 water leaks were found in three sections of the tunnel, but the project's consultant said they were not serious and would not affect the tunnel's quality.