By Jessica Kartalija

PHILADELPHIA (CBS) — In these uncertain times, signs of hope have popped up across Philadelphia. CBS3 met some of the people behind them.

Buildings darkened by the pandemic got a splash of color Wednesday morning.

READ MORE: Police: Body Found In Ocean Off New Jersey Identified As Man Missing For 4 Days

“As I was going through Center City, I saw all these boarded-up businesses. I thought, ‘Why don’t we put up some big posters on these walls?'” Visit Philly CEO Jeff Guaracino said.

They’re giant thank you notes, love letters, to the men and women who keep our city going.

Guaracino said it was Mayor Jim Kenney’s idea. He wanted to start a thank you campaign for the frontline fighters.

Coronavirus New Jersey: More Than 40 Breweries Joining Together To Help People Without Work in Hospitality Industry

Yes, the health care workers, but also the grocery store employees, cleaning crews, transportation drivers and more.

Visit Philly worked with artists to design the posters and on Wednesday morning, two other artists plastered them around town.

READ MORE: CBS3 Pet Project: As Halloween Approaches, Remember Not All Dogs Will Enjoy Wearing Costumes

Credit: CBS3

Symone Salib was one of them.

“We had so many people just stopping, even police officers. There was a cop on a horse who passed us on Chestnut Street by the A.C. Moore and he was like ‘good job!'” Salib said.

After being quarantined inside, Salib says the project took on a deeper meaning.

“Are you going to be a person to bring someone else down or are you going to be someone to help other people? And I hope that I can be someone to help other people,” she said.

The posters will stay up as long as the businesses are closed and buildings are boarded up. Hopefully, it won’t be for long.

MORE NEWS: AIDS Walk Philly, Region's Largest HIV Awareness Event, Underway At Art Museum

“We’ll be very happy on the day that we can help our business owners take down those boarded-up windows and take down those thank you posters, and then say thank you to our friends and family and colleagues we haven’t seen in a while,” Guaracino said.

Jessica Kartalija