The organizers of a 9/11 charity founded in honor of a fallen first responder planned to host their second annual stair climb fundraiser at One World Trade Center this May, but they've now been told that the event is a logistical inconvenience and can't go off as planned.

The Tunnel to Towers Foundation honors Stephen Siller, a firefighter who had just finished his shift in Park Slope when the planes hit the World Trade Center on September 11th. Though he was off duty, he drove toward Manhattan, but discovered that the Brooklyn Battery Tunnel was closed to cars. Carrying 60 pounds of gear, he ran through the tunnel toward the towers, and was seen last at West Street. In his memory, the organization has hosted a series of 5Ks, and, last year, the first stair climb at One WTC, which raised $500,000 for first responders and veterans.

Frank Siller, brother to Stephen and CEO of Tunnel to Towers, said that this year's stair climb was tentatively set for May 15, and that the organization had "attended meetings, participated in conference calls, dotted every i and crossed every t, and were led to believe that all systems were go, with the exception of a few formalities." But then on Friday, the foundation was informed that the event was a no-go, due to staffing and security logistics, among other concerns.

According to Jordan Barowitz, a spokesman for the Durst Organization (which owns One WTC, along with the Port Authority), last year's event didn't go quite as smoothly as Siller believed.

"As we learned from last year's event, the unique design and security requirement of One World Trade Center make stair-climbs extraordinarily challenging," Barowitz said. "With more tenants, the logistics are even more complex this year."

But Tunnel to Towers isn't buying it. COO John Hodge penned letters to Governors Cuomo and Christie, asking them to intervene on behalf of the Port Authority, which co-owns the building. In his letters to the governors, Hodge called the Durst Organization's excuses "disingenuous," saying that the foundation successfully navigated those obstacles during last year's stair climb. He's also said that he thinks the organization is prioritizing its desire to lease the building's remaining space over the charity event, despite the fact that the billions of taxpayer dollars that funded the building's construction should really make it "The People's Building."

"It is incredible...that civil servants were willing to give up their lives in order to save total strangers, and the management of One World Trade Center is not willing to give up the building at 5 a.m. on a Sunday morning because it is potentially inconvenient for them," Hodge said.

In a statement, Governor Cuomo said that he is "confident that remaining issues will be resolved so the event can happen again this year," though it was not immediately clear if that means that the Port Authority will override the Durst Organization's decision to reject the climb.