BOSTON -- This is about payback. The good kind of payback.
Ever grateful that Boston police officers volunteered to help their New York brethren in the aftermath of the terrorist attacks of Sept. 11, 2001, off-duty cops from New York's police unions are here in solidarity.
"They came to help us after 9/11, so now we're here to return the favor and support them," Patrick J. Lynch, head of the NYPD's rank-and-file union, the Patrolmen's Benevolent Association, said near the scene of Monday's bombings.
Both the union and its Port Authority police counterpart drove to Boston with canteen trailers and food trucks to provide exhausted Boston officers a respite from the kinds of grueling, long shifts New York police know all too well.
Thursday, one Boston officer after another -- many of whom were down the block when Monday's twin bombs detonated, killed three and injured more than 170 -- made pilgrimages to the canteens, exhausted from emotion and fatigue.
Greeting them at the corner of Boylston and Berkeley streets was pizza, coffee, burgers, sandwiches, brotherhood, camaraderie and understanding.
The Port Authority PBA's mental well-being counselor made the trip in case any Boston officers needed a professional to talk to.
Port Authority Police Officer Troy Lopez, 36, of West Babylon gestured toward a group of uniformed Boston officers eating pizza and swapping war stories.
"Right after 9/11, they were there. I remember seeing guys from Boston in uniform -- in full uniform -- just like that," Lopez said. "They were asking us if we needed anything, 'What can we do for you?' So this is our way of paying back."
Robert Paulsen, 39, of Bellport, said the Port Authority PBA brought about nine officers to Boston, several of whom were assigned to post-9/11 duty. Many more wanted to join the mission to Boston than could make the trip.
"I try to take the good away from it -- that we all come together and rise to the top," Paulsen said.
Both Lopez and Paulsen were with the NYPD during 9/11 and have since gone to the Port Authority police, where they're assigned to Kennedy Airport.
Thursday, two Boston police officers who had been posted a block from the finish line Monday when the blasts detonated were back, this time standing sentry at a crime scene.
"Wanna start a hamburger for them?" Lopez asked Paulsen.
Paulsen retrieved a refrigerated beef patty from the canteen, lifted up the lid of the Weber grill and started cooking.