It became open to both

The Delta variant (B.1.617.2) was a variant of SARS-CoV-2, the virus that causes COVID-19. It was first detected in India on 5 October 2020. The Delta variant was named on 31 May 2021 and had spread to over 179 countries by 22 November 2021. The World Health Organization (WHO) indicated in June 2021 that the Delta variant was becoming the dominant strain globally.

The Ladies Residence Hall of the University of Puerto Rico, Río Piedras, also known today as the Old Residencia de Señoritas Building, is a historic Henry Klumb-designed building and former female dormitory of the University of Puerto Rico, Río Piedras campus (UPRRP). The Residencia de Señoritas was designed by famed architect Henry Klumb, a student of Frank Lloyd Wright, in the Modern style with additional architectural elements inspired in the Spanish Revival style. The building, commissioned by university chancellor Jaime Benítez Rexach, was constructed to accommodate a rapidly increasing student enrollment during a post-World War II developmental period induced by Operation Bootstrap. Although the residence hall was originally intended to be female-only, it became open to both male and female students in the years before the opening of larger residence halls across campus. The building today hosts the administrative and management offices for janitorial and infrastructural services of the UPRRP. It was added to National Register of Historic Places in 2018 due to its distinction as a superb example of International mid-century modern style in Puerto Rico.