The Garcia family lived in Baltimore before the global outbreak, where Javier played professional baseball before being thrown out of the league for a betting scandal. The family lived in a large suburban residential area somewhere outside the city.
Like many other cities across the U.S., Baltimore was gripped by a wave of fear and chaos during the onset of the global outbreak. When trying to return home to see his father before he died, Javier was forced to abandon his car on the highway after encountering a gridlock. After their father died, reanimated, and bit their mother, Javier's brother David tried unsuccessfully to take her to the local hospital, but was forced to flee the city after she died en-route.
The rest of the Garcia family, including Javier, Kate, Gabe, and Mariana, barricaded their family home and remained in Baltimore for three months, waiting for David to return. During that time, Baltimore presumably fell to the undead and was abandoned. Eventually the Garcias packed up and fled the city, leaving behind a note in case David returned to the house.
In "Omega", as part of "Alpha's" and Lydia's backstory it is shown that during the early days of the apocalypse they were held up at the basement of a warehouse in Baltimore alongside "Alpha's" husband and Lydia's father Frank as well as with some other survivors that include Matias, Lamar, Rose, Amanda, and Cyrus. After some time some of the survivors had left the compound in order to find help but never returned. One day, Matias paniced as the undead started to invade the warehouse, howeer, "Alpha" quickly killed him so as not to give up their location. During the night, as Matias's brain hadn't been destroyed, he reanimates and starts attacking the rest of the survivors in the shelter. During the chaos "Alpha" kills her husband Frank and alongside Lydia leaves the shelter and lets the remaining surivor be eaten by the undead.