The same Georgia State University art project responsible for the shutdown of an Atlanta overpass earlier in the week also forced authorities in Hapeville, several miles south of Atlanta, to evacuate businesses and call in a bomb squad Tuesday after a second camera was found attached to a different bridge in the south Fulton County town.

Residents and business owners told WSB-TV that the suspicious device – now known to be a homemade long-exposure camera – was discovered on a pedestrian bridge near Hapeville's train depot.

“There were a lot of officials, and a bomb squad,” business owner Ardina Pierre told WSB-TV.

“They totally stopped all the traffic both ways,” she said. “They even stopped the train.”

The tube-shaped device discovered duct-taped to the 14th Street Bridge over the Downtown Connector on Monday was actually a pinhole camera being used in a solargraphy project to track the rising and setting of the sun over a three-month period, Georgia State spokesman Don Hale said in an email to The Atlanta Journal-Constitution on Tuesday. There was no immediate word on how long the camera had been there.

“Students were instructed to take their cameras home and to place them in locations that would provide interesting scenes with bright sunlight,” Hale said. “The locations were selected by the students.”

It was up to each of the 18 students in the class to find a spot for their own project, the university said. The university was made aware of the art project Tuesday morning and, through its police department, immediately informed the Atlanta Police Department, Hale said.

Only a handful of the projects were mounted in public places, and the university and police were removing those Tuesday. No information was released on where those cameras were located, but a second one was found Tuesday attached to the pedestrian bridge in Hapeville.

At a news conference Tuesday afternoon, Atlanta police said the student responsible for taping the project to the bridge could be charged with reckless conduct once the investigation is complete.

Assistant Chief Shawn Jones said the small object looked like an “explosive device” to the APD and he asked the public – particularly university students – to refrain from putting objects up in public that could be mistaken for harmful devices.

As The AJC and other news outlets broadcast images of the object on the bridge Monday, social media was filled with speculation about what it could be. On PetaPixel, a photography enthusiast blog, someone correctly identified the item as a pinhole camera being used in the photography project.

“If you’re looking to do a solargraphy project by leaving a pinhole camera in a place for months, a bridge above a busy freeway is not a smart location choice,” Michael Zhang wrote in a blog post.

After news broke Tuesday morning that the “device” was actually a project, Twitter and Facebook were again the venue for those wanting to weigh in.

“If it stops 12 lanes of traffic it’s probably not art,” one person posted on Twitter.

A pinhole camera strapped to a bridge in Roanoke, Va., two years ago also brought out the bomb squad and shut down traffic before officials detonated the camera on railroad tracks below the bridge. Similar to the incident in Atlanta, police in Roanoke also received a report of a suspicious device strapped to the bridge.

— Staff writers Alexis Stevens, Steve Visser, David Markiewicz and Janel Davis contributed to this article.