Here is the basic series of events regarding Hazel's broken leg, from what I understand to be correct.
I took Nyla and Hazel to daycare Thursday morning. I sat Hazel in the Bumbo seat on the counter. I left. I returned home. I received a phone call from the daycare provider 5 minutes after I got home saying that Hazel flopped out of Bumbo seat when she was reaching for something (hadn't done this before, and never had that experience with Nyla) and then fell off counter. She was caught by a daycare staff person so that she did not hit the floor.

If she had hit the floor, I would have taken her to the doctor right
away. But since she didn't, and since she was not even crying anymore
when the daycare person called me, I thought it to be a major scare and
lesson learned, luckily without consequences. By the end of the day
Hazel did not seem herself, however she was just getting a new tooth and
starting to get a fever so I attributed any crabbiness to that. The
next day she had more of a fever, which I figured was another ear infection so I took her to the doctor because of that. I could tell that her leg was bothering her too that day but I thought she probably just got jerked a little when she was caught or was sore from the fall somehow, or from falling out of the Bumbo, etc. She was happy as happy can be at times so I didn't ever suspect anything serious. I would think a person with a broken bone would be kinda crabby most of the time. I'm sure I would be. So anyway, while we were at the doctor, I asked him to look her over to reassure me that everything was okay so we did an x-ray just to confirm. We went home and I didn't expect to hear anything again. About 4:00 when they called to say we needed to get back in there right away, I still didn't believe she broke her leg. (By the way, she does indeed have another ear infection and tomorrow we have an appointment with an ENT to see if she needs tubes in her ears.)
So back to the accident... Why was she on the counter, you ask? As ridiculous as it may sound, I actually felt like it was the safest place for her to be, temporarily and when someone has an eye on her. It's busy when everyone is arriving in the morning, the staff was tied up at the moment, and I thought for the few minutes while all the kids are together and before more staff arrive, Hazel would be better off up and out of the way (but right near where everyone was) rather than on the floor where she could get run over.
It was my mistake for putting Hazel in the Bumbo seat on the counter. She is getting too tall and too strong for it. However, after getting more details about what happened I'm starting to think that the fall had nothing to do with the actual break. The leg openings of the Bumbo can get a little snug on the baby's legs as they get bigger so that you can't pull them straight out or the seat will get hooked on their legs. You slide them out kind of like a high chair. Hazel's break is right above her knee where that leg opening hits her thigh. When she was reaching for something (which is how she got out), I wonder if one leg came out while the other was still stuck and the weight of her body jerked or twisted it out in such a way that it broke her leg. That really sounds like a freak accident, but it halfway makes sense to me since she didn't fall on the floor or have any bruising and the Bumbo was still sitting upright on the counter when it was all over. I don't know whether that's true or even possible, but I'll definitely think twice when I tell new moms that the Bumbo seat is (was) one of my favorite baby gear items.
Do we think that the daycare was negligent or not doing their job? Tyler and I are fully supportive of the daycare and their staff. Everyone there is doing a great job and we are happy to take our girls there. People make mistakes and accidents happen. We are fortunate that we can all learn from this without any serious long term consequences. We all feel so bad for Hazel, but she is getting along fine. It's amazing to watch how she deals with obstacles as they come. I think we can learn from that too.
More later...