PHOTOS: Connecticut City Residents Ordered to Evacuate After Dam Partially Collapses, Bringing Potential for Life-Threatening Floods

Mandatory evacuations were underway Wednesday morning after a partial dam break on the Yantic River below Fitchville Pond Dam in southeastern Connecticut that was causing major flooding as a major storm pummeled the state.

A Flash Flood Warning was posted until 10:45 a.m. on Wednesday due to the potential for life-threatening flooding in New London County.

State Emergency Management officials said areas of Norwich were under a mandatory evacuation order due to the situation. A middle school was being opened as a shelter.

Norwich Police warned commuters that numerous roads in and around the city had several feet of water on them. Several roads were closed.

Norwich Public Utilities took the Bean Hill Substation offline to avoid possible "catastrophic damage" to infrastructure causing 5,000 customers to lose power. About 200,000 people live in the Norwich region.

In a Facebook post, the power company said it was gathering additional information on the damage to the dam, and would provide additional updates later in the day.

The Naugatuck Police Department cautioned drivers that dirt and debris were covering several roads.

Waters on the Housatonic River in western Connecticut passed flood stage on Wednesday.

The Pomperaug River at Southbury was at a moderate flood stage on Wednesday morning, according to the National Weather Service. The area already had between 1 and 2.5 inches of rain early Wednesday morning.

Some state parks were closed on Wednesday due to water and debris.

The storm hitting Connecticut moved up the East Coast on Tuesday, leaving half a million people without power, and left behind flooding in several states.