How to prevent children from injuries?

As a mother, I always ask myself how to prevent my kid from injuries. It seems to be very hard to keep an eye on children all the time. Accident normally happen when we are just away for a few seconds. So ideally, providing a safe play ground is one of the best way to prevent injuries. However in reality, that is not easy as we may need to renovate our existing room. Few days ago, accident happen to my daughter. I went to the toilet and she suddenly rush to look for me and accidentally hit the edge of the TV rack. She was with her father at that time but her father was not aware of her sudden and fast move and that he can't do anything also. Both of us was shocked  to see a lots of blood coming out from her mouth. I am so scared and worried until my tear is coming out. We felt so helpless and don't know what to do for a moment. We then tried to stop the bleeding by using some cloth and carry her flat on my arm and gave her some water. Luckily the bleeding stop quickly after that and she also stopped crying. I never felt so scared, helpless and sad before. I really don't know what to do if something happen to her. After this incident, me and my hubby keep reminding ourself to take a good care of her and we wouldn't want the same happen again.