Nashua South assistant football coach Bill Monsen works with a player at a preseason practice a few years ago. Monsen passed away Tuesday after suffering complications following a heart attack on Thanksgiving. (Telegraph file photo)

NASHUA — The Nashua sports community — and sports community statewide — is in mourning as longtime Nashua High School South assistant football coach and former Panthers boys head lacrosse coach Bill Monsen passed away late Tuesday afternoon due to complications from a medical episode suffered on Thanksgiving morning.

“Words cannot explain the pain of our loss of Billy Monsen,” the Nashua South Football twitter account posted Tuesday night. “He was a great teacher and coach and an even better person. Please keep him and his family in your prayers. RIP Mons.”

Monsen, a graduate of the first class of Nashua North, had been the South offensive coordinator the last several years, and had been on the football staff for 18 years under head coach Scott Knight. He was the South boys lacrosse coach for 10 seasons but stepped down at the end of last season after guiding the Panthers to the Final Four and being named All-State Division I Co-Coach of the Year, and Telegraph Co-Coach of the Year. He has been a teacher at Nashua South the last eight years.

Monsen had been hospitalized ever since suffering the episode nearly three weeks ago, and a Go Fund Me had been set up to help his family with expenses. He was a football and lacrosse standout as a student at Nashua High School, before moving on to play at North after the school split into North-South in 2004-05. He is the only player to have scored touchdowns for both North and Nashua High.

“Coach Monsen impacted so many lives,” former South standout quarterback and current Panthers assistant coach Trevor Knight tweeted last night. “Words can’t really express this loss for the Nashua South community.

“From watching him as a player, getting coached by him and then coaching with him, every second we spent together was a privilege. I’ll miss you every day man.”

Monsen’s family — he leaves behind his wife, Taylor and young son Finn — issued the following statement on social media:

“Thank you for your love and never ending support over the last 19 days,” the statement said. “Earlier today, after a heroic fight, Bill passed away peacefully with Taylor by his side. Our hearts are broken and the world lost an amazing husband, father, son, friend, brother, coach and teacher.

“To say that Bill will be missed is an understatement. He was such an integral part of so many lives and made an immeasurable impact on everyone he came across…”

The Nashua Athletic Department also issued a statement on Twitter.

“Our hearts are broken today,” it said. “Losing Billy Monsen, a great teacher and coach, great person, husband and father. Please keep him and his family in your prayers.”

Tributes will no doubt be coming in from around state football and lacrosse circles, where Monsen was extremely well-respected.

“Very sad to hear this,” Londonderry head football coach Jimmy Lauzon said. “Thinking of Nashua South tonight. Thoughts and prayers for the Monsen family.”