Emergency crews rescued several people after they fell through the ice at Burr Mountain State Park in Torrington on Sunday and two of the people who were rescued have severe hypothermia.
Firefighters said there were six people on the ice and five fell through at some point.
Five of the people who had fallen were ice anglers and a bystander had also gotten stuck while attempting to help, authorities added.
When crews arrived, they found four people through the ice and two who were on the edge, about 30 to 40 feet back, holding onto a couple of them with ropes.
Fire crews started rescuing and took over for the two people who were holding the ropes so they could be rescued, authorities said. Those two people were transported to Charlotte Hungerford Hospital. Firefighters did not release details about any possible injuries.
Authorities said rescuers had a difficult time coming back to shore because the ice kept breaking. Eventually rescue crews got to the two people still in the water. Those two people were transported to Hartford Hospital by two LifeStars to be treated for severe hypothermia.
One firefighter was also transported to the hospital to be evaluated due to overexertion, but is expected to return to duty, fire officials said.
The remaining ice fishing equipment could not be removed from the ice due to the unstable nature of it and safety concerns, according to firefighters.
The Connecticut Department of Energy and Environmental Protection said the ice is around five to six inches thick around the edges of the lake, but the ice where the people were fishing was only an inch or so thick.
Firefighters do not recommend anyone go ice fishing at the lake for the near future.