The national K-12 science standards were reformed in April 2013. On March 8, 2017, the state of Louisiana's Board of Elementary and Secondary Education approved the rewrite of the science standards to align with these national standards, and they were implemented in the middle school science classes. In March 2020, the COVID-19 pandemic began and thrust all students into the virtual learning world. The purpose of this study was twofold: to investigate certain changes made to the science standards in Louisiana and to examine how the pandemic interrupted NGSS implementation in the classroom both with teachers who were familiar with the new standards and those new to the science classroom and the new standards. This phenomenological case study focused on 10 middle school teachers that taught science before, during, and after the pandemic. After the data from the interviews was collected and analyzed, it was revealed that the impact of the pandemic on science instruction in the middle school classroom consists of three major themes: (1) the implementation of the Louisiana Student Standards for Science focusing on (a) their explanation of LSSS, (b) the impact of switching to LSSS and (c) how effective they feel with teaching with LSSS, (2) the virtual platform focusing on (a) physical versus digital models and (b) post pandemic instruction and (3) student behavior focusing on (a) working together, (b) motivation and (c) student accountability. Study findings illustrated how easily change can occur in student and teacher behavior when an unexpected event occurs and highlighted how enduring the impact can be on all stakeholders in the K-12 system. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]