Gov. Phil Murphy has signed legislation aimed at helping first responders who helped out at Ground Zero following the Sept. 11 attacks.

The governor signed the bills Monday at Liberty State Park, across the Hudson River from the site of the 2001 attacks.

One measure permits volunteer first responders to qualify for disability pensions when they retire. It's aimed at helping those who were not on duty but who helped after the World Trade Center towers fell.

A legislative estimate says it's unclear how much the change would cost. It depends on how many retirees apply, and the estimate doesn't specify a possible number.

The other measure makes it easier for first responders to get workers' compensation by removing the burden of proving the cause of an illness in certain cases.

“We now know that the air at Ground Zero posed just as much a risk as the tangled remains of two once proud buildings. And slowly over the ensuing 18 years, the effects of breathing toxic fumes and particles in the moments and days following the 9/11 attacks have taken their toll on the health of too many of these heroes,” Murphy said.

The bills were named for Hackensack firefighter Thomas Canzanella and Clifton firefighter Bill Ricci.