Madison — A bus carrying 55 people from New York City to Mohegan Sun rolled over on Interstate 95 in Madison Monday afternoon, injuring 36 passengers and snarling traffic between Exits 61 and 62.

A Yale-New Haven Hospital spokesman said six patients were listed in critical condition. State police said the injuries are not considered life-threatening, and victims were transported to area medical facilities for treatment.

The northbound lanes of the highway were shut down between Exits 61 and 62 for several hours, but the road re-opened at 4:54 p.m., according to state police.

The 12:24 accident occurred just east of Exit 61 during a snowstorm that dropped about 4 inches in southeastern Connecticut.

The driver of the bus, Keyi Zhang, 63, of Flushing, N.Y., told police he was merging from the left lane to the right and lost control on the snow-covered road. He then struck the guardrail on the right side of the road. Zhang was transported to Shoreline Medical Center in Westbrook for treatment of a possible injury.  

Multiple ambulances arrived on scene to transport those with injuries to surrounding area hospitals, according to a state police spokeswoman, Trooper First Class Kelly Grant.

About 30 passengers were able to walk off the Dahlia tour bus, according to state police. Those who were uninjured were taken to a nearby warming center, and the Red Cross was on site to assist them, she said.

No other vehicles were involved in the accident. Dahlia is based in Boston.

Mark D'Antonio, media coordinator for Yale-New Haven Hospital, said the six patients with critical injuries were originally evaluated at Middlesex Hospital. Around 4:15 p.m., five were transported to Yale-New Haven Hospital, while the sixth was sent to Hartford Hospital.

In addition, he said, eight patients were admitted to Yale-New Haven Hospital with non-critical injuries.

Shortly after the accident, a DOT traffic camera showed a slew of ambulances and other emergency vehicles surrounding the bus, which was lying on its side off the right shoulder of the snowy road. By 2:45 p.m., just a few emergency vehicles remained around the bus.

The state police Collision Analysis and Reconstruction Section is assisting with the investigation. The National Transportation and Safety Board was also notified.

Between 2008 and 2013, the one-mile stretch that encompasses I-95 northbound’s Exit 61 had the highest rate of accidents from Branford through Old Saybrook, according to The Day’s analysis of data. The one-mile stretch had a rate of 1.2 accidents per million vehicles during that time period. 

In a Monday afternoon statement, Gov. Dannel P. Malloy said he was monitoring the situation closely.

"Our thoughts are with those who are injured, and we extend our gratitude to the first responders who are working to protect the safety of all those involved," Malloy said. "We urge all those who must travel to use added caution, allow extra time to travel and reduce speeds as conditions warrant."

According to Mohegan Sun spokesman Cody Chapman, additional buses coming to the casino from New York were rerouted and sent back to New York.

Ashley Polo, a spokeswoman with Foxwoods Resort Casino, said that casino had canceled all its incoming bus lines for the day.

Schools across the region were closed Monday and some municipalities, including New London and Norwich, issued parking bans.

In Ledyard, police said they had to help several drivers who were unable to keep driving because of poor road conditions and visibility.

The region likely will see additional light accumulations of snow through Thursday, followed by below-zero wind chills this weekend, according to Gary Lessor, a meteorologist who serves as the Western Connecticut State University Weather Center's assistant director.

l.boyle@theday.com

Twitter: @LindsayABoyle

k.drelich@theday.com

Twitter: @KimberlyDrelich