Natasha was in her and Steve's en-suite bathroom when the bomb hit.
With only a week left until her due date, Natasha was always extremely uncomfortable, had a difficult time falling asleep and staying asleep, and had to pee roughly every twenty minutes, depending on how active the baby was. She was constantly moody and exhausted, and she was so sick of Steve fussing over her that she was beginning to regret telling Steve that the Red Room had lied to her about being sterile.
At the time, telling him she could have children seemed like a good idea, but after she had discovered that their attempts to conceive had been successful, Steve had gone straight into high gear overprotective dad mode. He refused to let her do anything for herself, was constantly by her side, and insisted upon treating her like an invalid, despite the fact that she was more than capable of taking care of herself.
Still, having Steve as her husband definitely had its perks. He had incredibly gentle fingers which he used to give her the most wonderful back and foot massages she'd ever experienced, he was always willing to give her anything she was craving, no matter what hour of the day it was, and he was surprisingly knowledgeable when it came to pregnancy, which was very helpful in dealing with her pregnancy symptoms.
Now, as Nat's back muscles clenched and her stomach tightened with what she assumed was another uncomfortable but completely normal third trimester symptom, she contemplated waking Steve for a back massage, despite it being three in the morning.
As she was considering the pros and cons of doing so, one of the babies delivered a hard kick to her bladder.
Natasha sat up as quickly as possible, swung her legs over the side of the bed, and waddled as quickly as she could to the bathroom that was attached to her and Steve's private room at the compound, taking care to not wake her snoring husband. She hadn't fully decided whether she needed him right now, but the discomfort had passed, so she figured it could wait until morning.
After washing her hands, Nat lifted her shirt to admire her significant bump in the mirror. Bruce, who they had deemed qualified enough to be her doctor throughout her pregnancy, had explained to her earlier in her pregnancy that because she was carrying twins, her belly would be larger than most pregnant womens', but she hadn't expected that it would swell up quite as much as it had.
No wonder my back hurts so bad, Natasha speculated. These babies are making me huge!
Then, the bomb hit. It shook the entire compound, and collapsed the wall between the bathroom and the bedroom, throwing Nat against the opposite wall and causing part of the counter to fall and shatter against the floor.
Natasha, acting on nothing but instinct, dove between the toilet and the sink, curling around herself and praying it would be enough to protect the precious lives she was carrying.
After about twenty minutes of silence, Natasha cautiously uncurled herself and stood, wincing as a much stronger cramp gripped her swollen abdomen. As it intensified, she felt a release deep within and heard a gush of fluid splatter against the floor.
When Steve felt the bomb hit and the room begin to crumble around him, his first instinct was to protect Natasha. He rolled over, intending to protect his wife's body from falling debris with his own, only to discover that Nat was not in the bed.
Unsure whether or not another bomb would hit, and knowing that his room was more than likely the most severely affected, he dove under the bed and prayed that Nat had gone down to the kitchen for a midnight snack, grateful, for once, that she had been stubborn enough to drag her nine months pregnant self out of bed at three in the morning for a snack instead of just asking him to do it for her.
After about twenty-five minutes, Steve crawled out from under the bed.
"Natasha?" he called, rising to his feet. "Nat? Where are you?"
Suddenly, he remembered his cellphone. Quickly, he ran to the dresser where he had left it, and found that it had minimal damage. He pressed the button to call his wife, who was first on his contact list. She, of course, picked up on the first ring.
"Steve!?" she choked.
"Tasha!" he exclaimed. "Where are you?"
"I'm in the bathroom," she explained. "The wall's collapsed, I don't think I'll be able to get out."
"Oh, God," Steve breathed. "Okay. Just stay calm, honey, stress is bad for the babies. Now, you just hang tight, and I'll go get Tony. He might be able to-"
"Steve," Natasha interrupted. "I need you to get Bruce first."
"Dr. Banner?" Steve asked. "Why?"
"Because," she sighed. "My water just broke."