Middletown, Conn., February 8, 2010 — Around noontime Sunday, an explosion at a natural gas-fired power plant killed at least five people, leaving more injured or missing, according to media reports.

Safety officials are trying to determine the cause of the blast, which was possibly caused when plant workers purged excess gas from pipelines. The plant is located about 15 miles south of Hartford, Connecticut.

The incident happened at the Kleen Energy Systems LLC natural-gas power plant being built near the Connecticut River. The blast was heard and felt up to 20 miles away from the site of the plant.

Officials have said there is no immediate public health threat, and the FBI is not treating the incident as an act of terrorism.

Some sources have reported as many as 200 workers were inside or near the plant at the time of the incident.

The power plant, which was slated to enter commercial service this summer, is a two-unit, 620-MW rated Siemens combined cycle power plant. The plant’s two units can run on either oil or natural gas, and the plant has a connection to a natural gas pipeline.

Construction began on the plant in February 2008. The plant is owned by Kleen Energy Systems and White Rock Holdings Associates, LLC.

According to previous reports, the plant’s operator is North American Energy Services and the plant’s manager is Power Plant Management Services.