Son is too active or the negligence of teachers?

My son is 9month old and I send him to an infant care centre since Jan 2019 (6month old at that point of time) He had the transition of knowing how to crawl when he was 8months old. Isit even normal that my son had three falls at the centre within two months? Who am i to blame? The negligence of the teachers or is it that my son was exploring too much that he tends to knock himself?