Manchester High School dismissed early on Wednesday following what was initially described as a "medical emergency" at the school.
School officials later confirmed to Eyewitness News that security guard Barry "Mitch" Mitchell had died at the school.
They said it appears that Mitchell suffered a heart attack on Wednesday morning.
"Our thoughts and prayers for his family," Manchester Schools posted to its Twitter account.
School officials said counseling is available for students on Thursday.
Anyone who walked the halls over the last 18 years knew Mitch.
He was loved by everyone and seemed to have made real, positive connections in the lives of so many students, past and present.
“Everybody knew him. He knew and cared for everybody he came in contact with. Very good understanding of all the kids who came through the school system, he seemed to know everybody,” said Manchester Police Capt. Chris Davis.
Davis worked alongside Mitch in the past, and knows the loss stings the community because for many, he was more than a security guard.
He was a man who always provided structure and values, especially in cases where they weren’t always there.
“A big influence, and I'm sure he was a father figure to many students, but a huge influence to many students coming through the doors of the high school,” Davis said.
Hundreds of people, including his family, gathered at the school on Wednesday evening for a vigil.
"Mitch was the best dad ever. I love him and he always brought a smile to my face," said Mitchell's 11-year-old son Barry.
Eddie Agosto, who graduated the high school in 2003, helped organize the vigil. He says Mitch spent his 18 years as a security guard shaping thousands of lives.
“He got a lot of people to get on the right path. A lot of guys were going down the wrong paths. He was not only a security (guard), he was a counselor that we can talk to,” Agosto said.
A former student set up a GoFundMe page to help out Mitchell's family. It can be found here.
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