On Sunday, Laura Mazur and Jessica Robertson were photographed by Dan Heckert as they finished the marathon holding each other's hand.
Heckert was at the 25-mile cheer station when he and others noticed the women together.
The two women -- Mazur running her 12th marathon and Robertson, her first -- were the last two runners and were helping each other finish, more than seven hours after the race had started. Before the race, the two had been complete strangers.
Robertson said she and Mazur had promised each other not to leave the other and to cross the finish line together, no matter what.
As the women ran, police officers rode on bikes beside them and a patrol SUV and ambulance could be seen driving behind them.
"Oh, yeah! Go!" one woman could be heard yelling as the duo ran by. "You guys look so amazing!"
"This is what the Pittsburgh running community is all about," said Dan Heckert, who took the photo and posted it to Facebook on May 6. I am constantly in awe about how much of a family this group is and how rewarding it is to cheer other runners along their journey. … These two ladies showed what it means to never quit,"
"Crossing the finish line hand-in-hand with Laura was truly an amazing moment. It showed me that I'm stronger than I knew and that I can accomplish anything with friends and family in my corner," Robertson of Braddock, Pennsylvania, told ABC News Thursday.
Mazur of New Bremen, Ohio, thanked the city for keeping the race intact that day and letting her and Robertson finish.
"They could've torn it down at any time but, you know, all the mile markers were intact. All the water was still there and we just got to finish like everybody else and I really appreciate that," she said.
She also thanked Robertson for being beside her the whole time that day.
"I'll hold your hand anytime, honey," she said.