LIV Golf is officially underway with the league's three-day invitational series winding down. The Saudi Arabia-backed league drew in golfers from all over, including many stars from the PGA Tour.

The golfers' controversial decision to ditch the PGA Tour for LIV Golf resulted in suspensions from the league. Some are even being accused of betraying the United States by 9/11 Families United.

According to their website, 9/11 Families United is a “coalition of families and survivors of the worst-ever terrorist attacks on American soil,” the attacks on September 11, 2001.

The New York Post reports that the coalition sent a letter to representatives of Phil Mickelson, Dustin Johnson, Bryson DeChambeau, Patrick Reed, and Kevin Na scolding them for competing in the LIV Golf Invitational Series.

“As a freedom-loving American, I am grateful to have the freedom of choice where I work and who I work for, and I respect your right as well,” the organization's national chair, Terry Strada, wrote (all direct quotes courtesy of the New York Post). She is a widowed mother of three. Her husband, Tom, was a victim of the 9/11 attacks.

“As you may know, Osama bin Laden and 15 of the 19 September 11 hijackers were Saudis…Given Saudi Arabia’s role in the death of our loved ones and those injured on 9/11—your fellow Americans—we are angered that you are so willing to help the Saudis cover up this history in their request for ‘respectability.’  When you partner with the Saudis, you become complicit with their whitewash,” Strada wrote to the LIV Golf competitors.

Many golfers who joined LIV Golf hope that the PGA Tour will change its rules to allow them to take part in both leagues. However, 9/11 Families United doesn't see things that way.

“It is absurd for any American who chooses Saudi oil money over the September 11 community to think that these exceptions should be made, and we will be sure to say so publicly should you pursue that path under the misguided notion that your betrayal will go unnoticed.”