PITTSBURGH (KDKA) – As workers put the finishing touches on the race route, runners began gathering Saturday morning for the first races of the Pittsburgh Marathon weekend in downtown Pittsburgh.

The Pittsburgh Marathon weekend is underway, however, the main marathon is on Sunday. But on Saturday morning runners of all ages gathered in downtown Pittsburgh for the 5K run, toddler trot, kids marathon and pet walk.

“We’ll probably see about 18,000 to 20,000 runners today alone,” said Patrice Matamoros, Pittsburgh Three Rivers Marathon CEO.

RELATED STORIES:

Workers were busy all week preparing to host thousands of runners and spectators over the course of the weekend.

Festivities began Saturday morning at 8 a.m. as runners participated in the 5K that started on the North Shore. Runners began outside of PNC Park and ran through the streets of Pittsburgh and over some of the iconic bridges before crossing the finish line downtown.

https://platform.twitter.com/widgets.js

Winners of the 5K were Sean Battis with a time of 16:54 and Laura Harnish 18:11.

“It’s really a family day,” said Matamoros.

Children were able to participate in the sold-out one-mile kids marathon. More than 7,000 children participated in the event. Staff at the marathon say this race is the biggest kids marathon in the nation.

“This is our biggest Kids Marathon that we’ve ever had and now it’s the biggest Kids Marathon in the country,” said Allison Corbett, Pittsburgh Three Rivers Communications Director.

Pittsburgh Steelers linebacker T. J. Watt and quarterback Mason Rudolph took part in the race to cheer on the kids running.

More people running in this weekends races and spending time in Pittsburgh means more money.

“This year the economic impact is going to be about 13 million dollars for the city of Pittsburgh. The hotels are absolutely sold out, all of the restaurants are going to be busy all weekend long,” said Corbett.

KDKA spoke to Angel Randolph, a Lyft driver, who says business has been good today thanks to the marathon, but driving around has been challenging.

“I have been out since about 6 o’clock this morning,” said Angel Randolph, a Lyft driver. “I had a girl today that I was supposed to pick up at the point and it was so blocked off I literally had to park the car and walk and meet her and bring her back to the car. So it’s been worth it financially, but it’s been a little frustrating.”

Sunday morning runners will assemble for the main event, the 26.2 mile Pittsburgh Marathon. Beginning at 7:05 a.m. Sunday morning, runners will run throughout several parts of the city before finishing downtown.