-Crying so hard they are not breathing enough; causing brain damage
-house could catch fire
-Someone breaks in & kidnaps the baby
-If there is a pet it could scratch/bite/kill the baby
-If it is during hot weather baby could overheat & sustain brain damage
- could electrocute himself by messing with electrical sockets, chewing on electrical wires
-baby can pull something on top of himself such as the TV
-could find items which he tries to eat & chokes
- could fall down & get head injuries, cuts, bruises scrapes broken bones etc.
-could possibly find & ingest household substances like soap, bug spray etc.
-could get himself stuck in some crevice for instance in between the wall and the bed, or between the cushions of the sofa; & suffocate
-could become entangled in things such as shoelaces or something like that; & strangle
-could fall into the toilet & drown
-could get bitten by a poisonous spider, snake, insect etc.
Not to mention all the psychological damage; I mean the poor thing would be very traumatized mentally, & would probably suffer long term anxiety .