The singer was performing in Atlanta Saturday, where State Farm Arena seemed to be packed to the gills with fans -- especially down below near where she was performing ... and where one gal apparently started getting crushed in the pit.

Check out this video we got of the moment BE paused everything once she became aware of what was going on ... it seems the lady in question was having trouble breathing, and needed an inhaler.

Luckily, Billie actually had one on hand ... and instructed the stage crew to get it to her ASAP. While the fan was being attended to, Billie settled down the crowd, told them to take a deep breath and step back -- at the same time, noting she wants to take care of her own ... something she's made sure to do in past concerts of hers as well, dating back years.

Then came a shot at what was clearly aimed at Travis Scott, with Billie saying ... "I wait for people to be okay before I keep going." That got huge cheers from the audience.

Of course, she's referencing the fact that Travis' November set continued for several minutes after the event was declared a mass casualty event -- with many suspecting TS was aware of what was going on. He's strongly denied that, claiming ignorance to the severity of things.

What's interesting here is the fact that Billie is replacing Travis at Coachella this year. Although an official announcement has yet to be made, the cat's outta the bag -- he got bumped amid the controversy -- other headliners dropped out too, FWIW -- and BE's one of the new artists who've been tapped in their stead.