MIDDLETOWN, CONNECTICUT (BNO NEWS) — A large explosion rocked a power plant in the city of Middletown in Connecticut on Sunday, killing at least two people and injuring scores of others.

The natural gas explosion happened around 11.26 a.m. local time at the Kleen Energy Power Plant on River Road, a 620 megawatt gas-fired power plant which is currently under construction. A Middletown Police Department official said testing was ongoing at the plant at the time of the explosion, “but, obviously something went wrong,” he said. “A lot of mutual aid is coming in.”

Plant manager Gordon Holk confirmed at least two workers had been killed. He said crews were conducting gas blows, a practice used to clean pipelines. Holk said there were injuries, and said an unknown number of people are still unaccounted for. “A search and rescue of the rubble is underway,” he said.

The manager said the explosion caused damage to the construction site and nearby buildings. Holk said an investigation into the cause of the blast is underway.

The official death toll as of 3.30 p.m. EST stood at two, while at least twelve people were confirmed to have been injured. A spokeswoman for Middletown Mayor Giuliano said there were “numerous” injuries, but had no exact figures. The death toll is expected to rise.

Middlesex Hospital spokesman Brian Albert said it received 11 patients. Two of them were later sent home with minor injuries, while one person was transported to Hartford Hospital with extensive injuries. Doctors were still evaluating the eight other injured.

Hartford Hospital spokeswoman Michaela Donnelly said it had received two patients, including the patient who was transported to the hospital from Middlesex Hospital.

Local media reports earlier said as many as 50 people had been killed, and more than 250 others injured. Al Santostefano, the Middletown Deputy Fire Marshal, said such numbers were not accurate. Santostefano said less than 50 people were at the site, and said some walked away alive. He said a search and rescue operation is continuing.

Connecticut Governor Rell is en-route to the scene of the explosion and is expected to arrive there around 3 p.m. EST, according to Donna Tommelleo, a spokeswoman for the governor. Governor Rell has spoken by telephone with the Mayor of Middletown and the Chief of the Middletown Fire Department.

Tommelleo said Governor Rell has activated the Emergency Operations Center in Hartford which is being staffed by the state Department of Emergency Management, Homeland Security (DEMHS), the Department of Public Health (DPH), the National Guard and the Connecticut State Police. Tommelleo said Governor Rell will assess the situation when she arrives, and did not know if she will declare a state of emergency.

Governor Rell also activated the Urban Search and Rescue Team. The Department of Public Health is providing tents at the scene for shelter and medical triage.

Middletown Mayor Sebastian Giuliano is also on scene to assess the situation. He said there is no public health threat. “Health Department officials and State DEP are on site and there is no issue with air quality or public drinking water supplies,” his office said. Giuliano said no terrorism is suspected.

The Middletown Fire Department said departments from all over the region are assisting local emergency responders, and hospitals in the area were put on stand by to receive casualties. The blast, which was felt as many as ten miles away, caused a fire which is now out.

The Red Cross is also on scene to provide crisis counseling. The public is asked to stay away from the area to allow emergency vehicles to proceed.

Fire department officials are planning to hold a news conference, but it is unclear when it will take place. It was earlier scheduled to start before 3 p.m. EST.

Image via @jimheem