Casey knew it was going to blow. The propane tanks had nowhere to release the gas except into the flames, he realized as fear rose in him. He hoped Gabby was out of the building, knowing it wouldn't bode well if she was inside. He heard the explosion and felt the ceiling cave in on him. His men had been silent in that moment, possibly the last sound they'd hear was the building collapsing.

When he opened his eyes, he could hear PASS alarms going off around him, including his own. Grunts could be heard as they turned off one by one until his was the only one remaining.

"Casey!" Hermann yelled from beside him, the rubble moving and Hermann surfacing. Casey wanted to call out, but he felt he was suffocating, his mask tinting his vision red. "We're coming to get ya'!" he called. He could feel the rubble around him move, and heard the gasps of the men of Truck 81 when they saw him.

"Mayday! Mayday!" Hermann called in the radio. "Firefighter down. Penetrative injury to chest! Mayday! Mayday!" Hermann's voice faded from Casey's ears.

Gabby heard Hermann through Boden's radio. She wasn't sure who it was, but she hoped it wasn't Casey. Shay was on the way to the hospital in another ambulance with Severide, not sure if she was going to make it. That left her with a paramedic from another ambulance. She grabbed the backboard, waiting for Boden's orders.

"Mills, are you able to come and get the pack?" Boden asked, waiting for a response. He knew it was too dangerous to send Gabby and the other paramedic into the building with the risk of further collapse.

"Yeah, I'm coming out," he told Boden, standing from Casey and rushing out. Boden walked away from Gabby. "Hermann, who's the man down?" he asked, wanting to know before the men brought him out.

"It's Casey, Chief. Doesn't look good." Boden sighed solemnly as he thought of what to tell Mills.

"Mills, you do not tell Dawson who it is. If asked, you say you didn't get see before I called you out. Is that clear?" he growled. A faint 'yes sir' replied a few seconds before Mills exited the building and jogged over to Gabby, taking everything from her. She didn't dare ask who it was, scared to know.

As Mills rushed back into the building, he realized how much Casey meant to Gabby, and that meant he'd do everything he could. He laid the backboard out and opened the pack. As he assessed the situation, he knew it was grim. On a piece of rubble there was a thin lead pipe which landed directly on Casey's chest.

He handed the c-collar to Hermann, who placed it on Casey as Mills took the mask off of him. Mills could tell that there was also a head injury, based on the amount of blood in the mask and on Casey's face.

"We have to lay him on his side, or the pipe could cause more damage," Mills told them. "Hermann, I need you to get his feet. Otis, his head. Mouch, his middle. I'm going to focus on keeping the pipe as stationary as possible. On three, we roll him onto the backboard." Everyone nodded as they took their positions, waiting for the call. "One. Two. Three," he said, as they all rolled Casey, who woke suddenly with a scream of agony. Hermann secured the straps to keep him in place. "You guys are going to lift, along with Cruz. I'm going to keep the pipe steady. On three again," he reiterated, getting in a crouching position. "One. Two. Three," he finished as they lifted. He grabbed the pack and threw it over his shoulder. "Stay as steady as possible. We don't need this moving," he noted as they made their way to the exit. He didn't want to see Gabby's face when they exited, but knew he would.

"Penetrative injury caused by lead pipe, head injury caused from the building collapse, unresponsive until moved, but then lost consciousness again," Mills told Gabby, not daring to look at her.

"Get him onto the stretcher," she told the guys, getting into the back of the ambulance. "And you, whoever you are," she said to the other paramedic, "you better fucking drive like you never have before," almost coming out as a growl. He nodded, and got in the front as Truck 81 loaded him into the ambulance. "Mills, with me," she said. He got in the back, and Hermann slammed the doors behind him.

Everybody had been sitting in the waiting room, waiting. Both Shay and Casey were in critical condition, and nobody knew how it was going to end. Severide and Dawson sat on a bench, Gabby curled into the man as she slept. It had been hours since the collapse, but no news came. Boden assumed no news was decent news, but also knew it meant endless worry.

The first doctor to come out had called Leslie's name. "We did everything we could, but there's been no brain activity since she got here. I'm sorry," he told them solemnly. Tears welled up in Gabby's eyes as she curled closer into Kelly, who stroked her hair while sobbing. Losing one was losing one too many, and Mills knew it was a possibility that they'd lose two.

Everyone had fallen asleep by the time the second doctor had come out, calling Casey's name. Gabby was the first to react.

"I'm his fiance," she told him, waiting for the news.

"Let's talk in private," he told her, ushering her into another room. She sat on a couch situated by the window, pulling her knees up to her chest.

He sat across from her in a chair, wringing his hands together. "As you know, as the paramedic at the scene, he had a penetrative injury to his chest." She nodded, knowing he was talking about the pipe. "Well, the pipe went through both the aorta and the pulmonary artery. When we removed the pipe, there was nothing we could do that could possibly repair the damage. We tried, but he bled out too quickly. I'm sorry," he told her. She didn't believe it, couldn't believe it. The pipe had seemed to have been nowhere near his heart.

"I want to see him," she said, almost numbly as she looked up at the doctor.

"I don't think that's-" he started, but was cut off with a growl of the word 'now.' He nodded, leading her to the elevator and to the morgue. She felt numb, like none of this could possibly be happening. One minute he was proposing, the next she was being told he was dead. It made no sense in her mind.

"I'll be in the hall when you're ready," the doctor told her, pulling back the sheet and stepping out. This wasn't the type of behavior he saw in people after loss.

She stood there, unsure of what to do. Matt was so pale and cold, and she knew he wouldn't wake up, but a part of her hoped and wished he would. There was no way for her to understand how this had happened, how things could change in the blink of an eye, but they had.

Tears streamed down her face as she stroked his cheek, that hope still in her, but she knew it was useless. Matt was never going to wake up, never going to tell her he loved her, never going to get married to her or have children or have the life he deserved because it was cut too short. She hated God for this, hated Boden and Mills and herself because there had to be someway they could have saved him. If Boden hadn't sent them in or if Mills had gotten there sooner. But she knew that the 'what if's were only that. They were a fantasy her mind concocted to try and figure it all out, when there was nothing to figure out.

She walked back out to the doctor, ready to tell the family of Firehouse 51 that another brother was dead. She didn't know how it would go, but it was time to be done.

A week had passed since Shay and Casey's deaths. Firehouse 51 was in mourning, but had accepted it for what it was - heroes sacrificing themselves for the greater good. For Gabby, it was different. She hadn't come to an acceptance, in fact, she was still in denial. Boden had allowed her to take time off to grieve, but it hadn't relented for her.

Kelly kept telling Boden that something was wrong. He had stayed with Gabby for that week since the loss, and she hadn't left her room or eaten. But he knew she was alive by the sobs he heard, the sobs of someone who had lost so much in one day.

"Are you ready?" he asked her as she stepped out of the room for the first time in a week, dressed in her dress blues. All she did was nod and take his hand as they made their way to the car.

It was warm when they reached the cemetery, Truck 81 and Ambulance 61 parked in the drive, flags hung from both. Gabby could hear people crying around her, but she couldn't. She had to stay strong for Matt, because he wouldn't want her to cry. She felt a hand on her shoulder, only to see Peter Mills looking down at her with a solemn look.

"Everybody, meet at Molly's," Hermann told the family of Firehouse 51, a pained look on his face. Nobody knew what he had in store for them.

When they arrived, they grabbed beers mostly and sat at the table Hermann had set up. "Shay and Casey were two people who kept us together," Hermann told them, "and both of them will be dearly missed." Everyone nodded in agreement. "But to mourn their deaths would be an insult, because they'd want us to celebrate their lives." He looked to Gabby.

"The last thing Casey said to me before we went into that building was at the firehouse when he said, 'I'm gonna marry her.' He loved you so much, and sometimes when we were in a building he would tell me he had to make it out for you." Tears welled up in his eyes. "He loved you so dearly, Gabby."

She looked away, only to see two cloths on the wall behind the bar. She stood and pulled them down, revealing the picture of her and Matt in front of the door of Molly's after he helped her get it. The other picture was of Leslie and Kelly at the firehouse. She wanted to be grateful, but the pictures reminded her of the loss they'd endured.

"I'm sorry, I can't," she said softly as she ran out Molly's. She didn't know what to do. Her best friend was dead, and so was the love of her life. Despite all the grieving she'd done over the past week, she managed to let out the most heart wrenching cry any of the family had ever heard. She didn't understand why this had to happen, why they had to loose the glue of the firehouse. She didn't understand why the happiest day of her life had to end up the saddest. None of it made sense to her anymore.

"I know it's hard," she heard Boden say from beside her. "Losing anyone is hard, but for some reason losing one of our own is harder. He was like a son to me, you know?" he said softly, placing a hand on her shoulder. "Everyone here are like my children. We're here for you, Gabriela, whatever you need, just give us the word." She nodded, understanding what he meant. "After you left the hospital, his doctor gave me his effects. I figured you'd want this," he told her handing her the ring box. More tears rolled down her face.

"He proposed, you know?" she said softly. "Before we got the call. I didn't have time to answer before we had to leave. He'll never know I'd say yes." She hugged Boden, sobbing into his chest. He stroked her hair, holding her and comforting her.

"There's no doubt in my mind he thought you'd say yes," he assured her. At that moment, she had a new hope. She knew she'd always love Matt, that nothing would change that or waiver it. She hoped that one day she'd look at a picture of them and think only happiness and love instead of anger and grief. She hoped that one day she would understand.