How dangerous is backyard boxing?

By backyard boxing i mean people who arent trained fighting with gloves were from ages 14-15 were not those big teenagers who look like 18 we look our age im 5'4 another guys about 5'6 the tallest is like 5'8 and were skinny they dont know how to fight so most likely theyll throw haymeakers and get tired easily which makes it safer right the fights should be short how unsafe would this be are we talking broken teeth, concussions and most feared a knockout i doubt were that strong but is this possible were also using padded gloves idont know if theyre 12' oz (youth) or 16' oz (pro) gloves