When a massive earthquake rocks Los Angeles, the first responders rush to rescue victims from a crumbling high-rise hotel both under the rubble and high above the ground. Athena must deal with wreckage from a collapsed freeway overpass and Maddie is thrown into the fire as she faces her first crisis as a 911 dispatcher.

The first responders continue to deal with the fallout of a massive earthquake and its deadly aftershocks. Athena tries to keep the peace as Bobby and team continue to rescue victims from a collapsing high-rise hotel, both under the rubble and high above the ground. Maddie 's first day on the job involves helping a pregnant couple deliver their baby safely.

Maddie goes for a ride-along with Athena in the hopes of being on the other end of a 9-1-1 call; Hen attempts to learn how to prevent her family from falling apart at the seams; disaster strikes at a military funeral and movie theater.

The holidays are naughty and nice for the first responders, who must deal with a stampede at a toy store, a mistletoe stunt gone awry and neighbors competing in a Christmas-light showdown. Meanwhile, Bobby contemplates his future with Athena, Chimney and Buck attempt to lift Maddie's spirits and Eddie must decide if he wants to give his son what he really wants for Christmas - a visit with his mom.

The First Responders rally together to search for a missing Maddie.

When Metro LA's 9-1-1 system is hit with a massive system-wide power outage, the call center must go old school in responding to emergencies. The first responders must deal with explosions in multiple homes and a difficult child birth. Meanwhile, Michael confronts Bobby about parenting his kids.

The first responders deal with a calamity at a chocolate factory; a mail bomb explosion; Eddie receives some surprising news from Shannon; Maddie contemplates her future in the call center.

The 118 deals with a situation where a stunt driver is placed in a precarious position, two mail bombs are detonated and a teenaged social influencer loses their mind; Eddie's family decides to visit; Buck confronts a deadly series of events.

Athena enlists the 118’s help when a teenager speeds out of control on the freeway. Meanwhile, a routine traffic stop uncovers a shocking kidnapping and Buck struggles with his recovery.

The team races to save workers in a high-rise during a fire drill, car accident victims, and siblings fighting over a family heirloom. Buck gives Bobby surprising news. Eddie helps Christopher deal with the trauma caused by the tsunami.

Athena and the 118 respond to bizarre emergency calls on Halloween, including a flock of crows terrorizing a field trip, an office employee having a close encounter with an eight-limbed creature and a ghost-like girl wandering a neighborhood.

The 118 responds to debris from a meteor shower crashing into an apartment building and a deadly fire caused by a hazardous waste truck crash inside a tunnel. Meanwhile, Hen struggles with guilt over her ambulance accident, Bobby introduces Eddie to an old friend to help with his anger and Maddie receives an urgent call for help.

The 118 responds to a viral stunt gone haywire, a disaster at a couple’s fishing trip and an epic first date fail. Meanwhile, Athena investigates a woman who doesn’t remember being shot in the head and Eddie is forced to have a difficult conversation with Christopher.

Accidents happen at a bowling alley and a home renovation; Athena pursues a car thief.

Maddie fears for herself and her co-workers when the call center is taken hostage.

The 118 races to rescue a little girl in a runaway hot air balloon and help with a city power outage caused by a hijacked tree-trimmer truck; Athena's investigation into a serial rapist case puts her life in jeopardy.

The 118 rush to save lives in the aftermath of a massive train derailment.

The Hollywood Reservoir dam breaks. The team adjusts to life during the pandemic.

In the aftermath of the dam break, massive mudslides wreak havoc throughout Los Angeles.

Athena investigates a mysterious murder during a neighborhood block party and the 118 rush to save lives endangered by a bomb threat. Meanwhile, Chimney has a hard time keeping secrets when Maddie and Buck's parents come to town.

The 118 believes their fabled firehouse superstition has come true when they have the day from hell with a never-ending series of bizarre emergency calls - Athena is in hot pursuit of a 118 firetruck; a man who duct-taped himself to freeway billboard, a garage full of fireworks and a restaurant manager destroying his own business. Meanwhile, Eddie feels a spark with Christopher's former teacher, but admits to Bobby he may not be ready to move on in his personal life just yet.

Athena and the 118 race to save lives after a drunk driver causes a deadly pile-up on the freeway. Meanwhile, Maddie goes into labor and Hen and Karen are devastated as they prepare their foster daughter, Nia, to be reunited with her birth mother.

The 118 responds to a series of calls dealing with parents and their children, including a disastrous birthday party thrown by a mommy blogger. Meanwhile, Athena and Michael talk to May about her past suicide attempt, Chimney and Maddie adjust to life with their newborn, and Hen and Karen are emotionally shattered as their foster daughter, Nia, is reunited with her birth mother.

The members of the 118 rush to the site of a hit-and-run that leaves a familiar face in critical condition. Meanwhile, with Buck's help, Athena investigates the case of a missing woman last seen in a casino and Josh recalls an emergency in 2006 that led him to become a 9-1-1 operator.

When a famous mystery writer dies, Athena, Bobby and the 118 respond to the chaos caused by a city-wide manhunt for buried treasure the author left behind.

A series of ransomware threats leads to an overabundance of emergencies for the 118, including a medevac helicopter crash at a hospital and an air-traffic control tower system failure. Meanwhile Athena must revisit her traumatic attack when the case of the realtor serial rapist goes to trial, Eddie suffers a health scare and Maddie's postpartum depression worsens.

As the citywide blackout continues to cause mayhem in Los Angeles, Athena races to save her family from a tragedy. Meanwhile, Eddie must make a difficult choice about his future, and Maddie makes a life-changing decision.

The members of the 118 arrive on the scene after a truck crashes into a high school homecoming parade. Meanwhile, Athena and Michael try to help Harry in the aftermath of his kidnapping, May is intimidated by returning call center legend, and Bobby gives a devastated Chimney advice regarding Maddie.

Responding to a fire at a prison, Bobby and the 118 find themselves trapped in a deadly riot

Bobby and the 118 race to save lives after an explosion rocks the hospital where Dr. David Hale is performing surgery. Meanwhile, Michael makes a life changing decision.

The members of the 118 are called to series of emergencies around Christmas Eve. Then, Eddie struggles with an emotional Christopher.

Athena, Bobby and the 118 "speed" to the rescue to save a family whose pick-up truck has been rigged with a pipe bomb which will detonate if the vehicle slows under 55 miles an hour. Meanwhile, Eddie has a rough transition into his new job, Buck makes an impulsive relationship decision and Hen is reluctant to accept her new partner in Chimney's absence.

Athena investigates a robbery at a gas station that takes an unexpected turn when the would-be victim turns the tables on her assailant. Meanwhile, Bobby and the 126 race to rescue a novice diver who panics while in a shark cage, and a house sitter terrified of spiders. Then, Eddie reaches his breaking point, Chimney returns to the 118 and Maddie shares some news with Buck, who realizes he has to come clean with Taylor.

The 118 races to the rescue when the 9-1-1 Call Center goes up in flames. Then, Bobby risks his life to save a trapped May, and Claudette, Buck and Eddie work together to help an injured electrician, and Chimney and his brother team up as firefighters for the first time.

Another day in the life of the 118, as its members race to rescue a cliffside wellness retreat guru after his followers turn on him. Then, they respond to an emergency call at an upscale hair salon. Meanwhile, Maddie contemplates returning to work, Eddie and May make decisions on their future, as do Buck and Taylor, and the 118 gathers for a surprise wedding.

When a blimp suffers mechanical failure and its engine catches fire, Athena and the 118 must rescue victims both inside and outside a packed sports stadium. Bobby and Athena drop off May on her first day of college and discuss honeymoon plans, while Maddie and Chimney go to couple's therapy.

Athena investigates when the same house is hit with two home invasion 9-1-1 calls within hours of each other. The 118 race to the rescue when a D-I-Y home renovation traps a man in an attic. Hen asks for a second chance with her medical school professor. Maddie and Chimney regret hiring a nanny for Jee-Yun after the woman completely takes over their apartment.

The Santa Ana winds bring in a variety of weirder-than-usual emergencies as the 118 respond to a family dog retrieving a severed hand and a young woman sleep-driving into the station. Bobby worries about his AA sponsor. Denny questions Hen and Karen about his biological parents. Chimney thinks he's found the perfect house for him and Maddie.

A dry thunderstorm rolls over LA, bringing in a series of lightning strike emergencies for the 118 and leaves a first responder's life hanging in the balance. Athena and May go undercover at the rehab facility to help Bobby with his investigation into his sponsor's mysterious death. Maddie dreads her parents visit to her and Chimney's new and unfinished house, while Chimney get a surprise of his own from a visiting Albert.

Despite the case being closed, Bobby is determined to prove his AA sponsor was murdered and bring his killer to justice; Meanwhile Buck struggles with his post-traumatic stress.

The 118 race to the rescue at emergencies when a fire breaks out in an accountant's office and a car crashes into a "living funeral." Athena is shocked when a suspect dies in her custody minutes after she arrests him; Buck is attracted to a death doula; Maddie and Chimney panic when they are audited by the IRS.

The 118 race to rescue two roommates desperately trying to find a needle in a haystack at a landfill, and help a woman whose nightmare dream suddenly becomes a painful reality. Athena and Maddie team-up to find a missing boy in a crowded mall; Chimney debates if the time is right to propose to Maddie.

A series of freeway car accidents leads to a catastrophic overpass collapse that endangers the lives of civilians and members of the 118.

Athena and Bobby set off on their honeymoon cruise, but when duty calls, their vacation is put on hold. Meanwhile, a fighter jet traps a civilian, and an unusual incident leaves a couple stuck together.