UPDATE 2-TransCanada contains W.Va. natgas pipeline blast, no injuries

(Recasts, adds statement from TransCanada and West Virginia environmental regulators)

June 7 (Reuters) - TransCanada Corp said it has isolated the section of Columbia Gas Transmission pipe that exploded early Thursday in Moundsville, West Virginia.

There were no employees at the site at the time of the blast around 4:15 a.m. EDT (0815 GMT) and no homes were in danger, officials from the Roberts Ridge Volunteer Fire Department told local news media.

The company said in a statement that its first priority was to protect the public and the environment.

Moundsville is located in Marshall County on the West Virginia panhandle on the Ohio-West Virginia border in the heart of the giant Marcellus and Utica natural gas shale formations.

TransCanada said the incident could impact about 1.3 billion cubic feet per day (bcfd) of gas service, according to a notice to customers using the pipeline.

One billion cubic feet is enough gas for about five million U.S. homes.

The company did not say when it expected the pipe to return to service, but said it was declaring a force majeure.

It was too soon for pipeline flow data to show any impact on the movement of gas through the area. The latest data from Thomson Reuters analysts showed West Virginia was producing about 4.8 bcfd of gas, about the same as earlier in the week.

The West Virginia Department of Environmental Protection (DEP) said it was investigating the explosion.

The 12,000-mile (19,312-kilometer) Columbia pipeline system, which TransCanada acquired in 2016, serves millions of customers from New York to the Gulf of Mexico. (Reporting by Arpan Varghese in Bengaluru and Scott DiSavino in New York; Editing by Bernadette Baum and Marguerita Choy)