Disheartening News, but not morbid yet

We woke Dad up this morning to get him weighed and to take his vitals. I brought the scale over to the bedside and we had him sit up. Mom was on one side and I was on the other and Dad put one foot on the scale. We told him to put the other foot on the scale, but he didn't have his hearing aids in and so we shouted a little louder because you get used to that. He didn't respond. He didn't even say anything to us. I started to shout at him saying, "Dad, Dad, do you hear me? Are you there Dad? You have to put your foot up. Dad? Do you want to sit down?" Something, anything to get him to respond. He still didn't respond. Then he looked up and his mouth went open wide and he became dead weight and went limp. So I grabbed a hold of him and guided him to the floor. He was sitting on his knees and Mom was concerned about his legs being hurt. I wanted to get him responsive first, so I told Mom to call 911. I said, "Dad are you with me? It's Erica. Do you know who I am?" He finally said, "Oh, my legs hurt." I said, "Ok, are you with me? Can I straighten you out?" He said that he knew me and I could straighten him out. An old schoolmate of mine was the first on the scene as he works for Bolton Volunteer Fire Department. I tell ya, they have been AMAZING! He's in the hospital now and they are taking chest x-rays. I hope that I didn't do anything to him. I asked him if he wanted to get up and he said yes, so I wrapped him up and lifted, but he shouted out in pain, so I put him back down and asked what hurt, and he said it hurt where I wrapped him up. I said, "Well, Dad, the only way I can get you up is if I wrap you up in a bear hug and pick you up, but I don't want to do it if it hurts you. We can wait. I don't want to break anything." Hopefully I didn't screw him up even more with that. That thought just crossed my mind. Hmmm.... It's possible that his blood pressure was just too low when he stood up, but it's also possible it might be more serious. I'll keep you posted on his progress and if he's admitted or not to the hospital.