The Fulton County Courthouse in Downtown Atlanta was briefly on lockdown March21 after a suspicious white substance was found inside an envelope addressed to District Attorney Fani Willis’ office.

According to WSB-TV, an employee opened the envelope around 2 p.m. and alerted authorities after finding a white substance inside.

The Atlanta Fire Department treated four people who complained of headaches but determined the substance was non-poisonous.

The lockdown was lifted after 3 p.m. and normal functions resumed at the courthouse on Pryor Street.

Check back for updates.

Collin Kelley is the executive editor of Atlanta Intown, Georgia Voice, and the Rough Draft newsletter. He has been a journalist for nearly four decades and is also an award-winning poet and novelist.