Athena Grant-Nash (née Carter) (Angela Bassett) is an LAPD patrol sergeant, and mother of May and Harry from her first marriage to Michael Grant.

Pepi Sonuga portrays a younger Athena during the flashback scenes of an episode of season 3 in which she learns that the weapon used to murder her fiancé has been found.

Robert "Bobby" Wade Nash (Peter Krause) is the Captain of Station 118 of the Los Angeles Fire Department and later Athena's husband.

Originally planning to commit suicide after saving 145 lives as atonement, his friendship/camaraderie with the members of the 118 and his blossoming relationship with Athena helps him put his demons to rest, and he becomes a beloved stepfather to May and Harry and a father figure to Buck.

Buck was an uncontrollable womanizer at first (which nearly cost him his job in Season 1, since he was using LAFD property to facilitate his liaisons), but after meeting Abby he started looking for serious relationships.

This gave Eva a reason to try to get custody of Denny, claiming Hen's infidelity proved that her household was unfit for her son.

Fellow firefighter, Tommy Kinard was also trapped inside, but was able to be saved before the explosion, thus Chimney earning the firehouse's respect.

His younger half-brother, Albert, makes a surprise visit after he secretly left South Korea to escape their father, whom he had been living with for awhile.

During a pile up on the highway, Maddie goes into labor and gives birth to their daughter, Jee-Yun, whom is named after Chimney's late mother.

In the eighth season, Maddie and Chimney become Mara Driskell's temporary foster parents in order to help Hen and Karen be able to still see her.

Maddie Han (née Buckley) (Jennifer Love Hewitt)[1] (season 2–present) is a 9-1-1 operator, Buck's sister, and Chimney's wife, who replaced Abby Clark as the series' main dispatcher.

Originally a nurse at a Boston hospital, Maddie fled to Los Angeles to escape her emotionally and physically abusive husband, Doug Kendall.

In the episode "The Taking of Dispatch 9-1-1", the call center is taken over by a group of thieves, holding the entire staff hostage in a planned heist.

In season five, Maddie's postpartum worsens and while giving Jee-Yun a bath, she accidentally lets her slip underwater due to dozing off.

She heads to Boston where she enters a program for women diagnosed with PPD for six months, and is absent for several episodes (Hewitt was on maternity leave).

[3][4] A Texas native, he served in the United States Army as a combat medic and moved to Los Angeles after being discharged, joining the 118 fresh out of the academy.

He served in Afghanistan and his combat experience is shown through his ability to think quickly on his feet even under duress with minimal back-up.

When he returned, Shannon left Texas to take care of her sick mom in California as well as escape her marital issues with Eddie.

Eddie struggles to juggle the life of a single dad to a kid with special needs, as well as the long work hours as a firefighter.

Buck introduces him to Carla Price, the home nurse of Abby Clark's late mother, Patricia, and she becomes a nanny and friend for the Diazes.

Eddie joins an illegal fight club to cope with his anger over Shannon's passing, and gets arrested after knocking one of his opponents out.

In the fifth season, Eddie starts experiencing panic attacks due to a multiple of things such as the thought of commitment to his then girlfriend, Ana Flores, and his shooting.

In "Brawl in Cell Block 9-1-1", he and Buck are taken hostage by two escaped prisoners, which leaves Eddie shaken by the end of the episode.

In the episode "Wrapped in Red", Christopher gets obsessed with having a perfect Christmas and expresses his fear of Eddie being dead next year.

Connie Britton had originally signed a one-year deal with 9-1-1, as she had just finished starring in Nashville and didn't want to do another series right away.

He had secretly left South Korea to escape his father's authoritarianism and came to Los Angeles to find his half-brother, Chimney.

After a camping trip with Bobby and Harry, Michael is persuaded into getting treatment for his cancer so he doesn't miss out on his kids' achievements like May's graduation.

Rockmond Dunbar exited the series midway through the fifth season due to FOX's COVID-19 vaccine mandate and his request for medical and religious exceptions being denied.

He later goes to live with Michael in Florida, but comes back to L.A. in the series' 100th episode after punching a store clerk and is now wanted by the police.

After she graduates high school, she decides to take time off before going to college and gets a job as a dispatcher in season four, despite Athena's initial resistance.