PITTSBURGH (KDKA) – While the U.S. is still reeling from the second mass shooting in less than 24 hours, Pittsburgh has been here before.

Exactly ten years ago today, on Aug. 4, 2009, George Sodini killed three people and injured more at a gym outside of Pittsburgh.

WATCH: Susan Koeppen’s report 10 years ago

A gunman reportedly walked into a fitness class at LA Fitness in Collier Township.

Police reported there were approximately 20 women taking a class at the time, and Sodini walked right in and started firing.

His body was found among the others.

More recently, a gunman opened fire at a synagogue in Squirrel Hill.

Mayor Bill Peduto, who was the mayor of Pittsburgh at the time of the Tree of Life synagogue shooting, tweeted about the Dayton, Ohio incident.

He said he woke up this morning to another mass shooting and he called Dayton Mayor Nan Whaley to offer support and advice Pittsburgh gained from the horrific experience of the Tree of Life massacre.

“Incredible that states & federal government continue to ignore this epidemic,” Mayor Peduto’s tweet read.

“Doing nothing will not solve the problem.”

Pittsburgh Mayor Bill Peduto’s Cheif of Staff Daniel Gilman also tweeted, reiterating support for Dayton Mayor Whaley, who Gilman called “a good friend.”

The tweet reads: “We will provide whatever support you need. We are in the fight together because enough is enough.”