The culprit responsible for shutting down a portion of East Bay Street for a few hours this morning? Baking Soda.

The harmless substance caused some concern after it was found in an envelope at the Charleston Historic Foundation. Authorities took plenty of precautionary measures, including quarantining about 20 people, before they were able to confirm what the powder was.

***UPDATE, 4:21 pm***: WCBD is reporting that the envelope was mailed from Finland.

You can read the full story from local media: