Rosalind O'Connor/NBC

Rosalind O’Connor/NBC(NEW YORK) — Saturday Night Live‘s Chris Redd, Veep‘s Sam Richardson, Late Night writer Amber Ruffin and Space Force writer Aasia LaShay Bullock are among the 19 black alumni and current employees of The Second City improv company demanding an investigation into alleged racism and sexual misconduct by the comedy institution.

The group, in an open letter obtained by Deadline, accuse the improv company of “erasure, racial discrimination, manipulation, pay inequity, tokenism, monetization of Black culture, and trauma-inducing experiences of Black artists…”

The letter calls for “A thorough investigation and removal of teachers, producers, directors and other administrative staff guilty of micro aggressions, racial transgressions, cultural appropriation, mental and verbal abuse against the Black artists who built your stages.”

The letter also calls for an investigation into “organization-wide and immediate removal of anybody guilty of sexual assault” and a “revision and proper accreditation” of the contributions of the black artists “who built your stages.”

The demand, signed by the 19 current and former Second City associates, comes on the heels of Second City CEO and co-owner Andrew Alexander’s resignation last week over accusations of institutional racism.