ATLANTA -- Even though there have been no specific known threats here, Atlanta and many other U.S. cities have ramped up security following Monday's explosions at the Boston Marathon.
Probably more than most, the Atlanta Track Club has taken the tragedy to heart and mind.
As organizers of the world's largest 10K race, they're already discussing how to beef up protection for the 60,000 runners who'll be in the July 4th Atlanta Journal Constitution Peachtree Road Race.
One of their board members was among many Atlanta runners who flew back from the Boston race on Tuesday.
"We are very sensitive about things that we may have to change for that race to make sure that we are sensitive to safety," Mike Wien told 11 Alive News.
The world's busiest airport, where many local runners returned from Boston on Tuesday, increased its security.
MARTA also said it's stepping up security and surveillance at bus and train stations.
The transit system's top preparedness man pointed out they regularly plan exercises to be ready for any kind of attack or emergency.
"Complacency kills, we recognize that and we don't want to ever be, you know, complacent to the point where we're caught off guard," said Sgt. Aston Greene, who heads MARTA's emergency preparedness.
Atlanta has seen its share of terrorism, like the 1996 Olympic bombing that killed two and injured many more or the 1958 bombing of the Temple on Peachtree Street.
Although they, too, know of no specific threats, the Anti-defamation League has reminded Jewish synagogues, schools and other organizations through the Southeast to keep their guard up.
"This shakes us out of our complacency and reminds us we have to be vigilant," ADL Southeast Regional Director Bill Nigut told 11 Alive.
Security was also increased for Tuesday night's Atlanta Braves and Atlanta Hawks games.
As usual, authorities urge the public to keep their eyes open and report anything suspicious.
Someone spotted a strange package at Turner Field a few hours before Tuesday night's Atlanta Braves game.
Atlanta Police checked it out and found it to be harmless, something that's probably happening all over the nation.