PHILADELPHIA (CBS) --  Members of a West Philadelphia church did something for the first time since the congregation formed in 1882. They talked about what to do if someone walked in with a gun.

Pastor Donald Moore came to Mount Carmel last year and after what happened over the summer in Charleston, his outlook changed.

"Nothing is off-limits anymore in our society," he said.

Nine people died inside Emanuel AME Church in Charleston, South Carolina. Worshippers were inside for a Wednesday night service, when police say 21-year-old Dylann Roof walked in and opened fire.

"We were here that night for Bible study when the shooting happened down there," Mount Carmel member Alice Thomas said.

Thomas comes to Mount Carmel every week and has for the past 40 years. She listened as a counterterrorism detective gave crucial information about what to do should someone come to the church with a gun.

"These people are preparing themselves, and we are preparing on the outside and the two of us can meet in the middle," Detective Joseph Rovnan with PPD Counterterrorism told Eyewitness News.

Rovnan said he's received numerous calls from churches interested in similar training.