Can a company fire you with no written/verbal warning?

I was fired today from Wild Waves Theme park. They say in the handbook that they have to give you warnings at certain points but they did not give me any work. Then I went today and I went to clock in and they told me to sit down and they fired me. Also one of those days my best friend/cousins ex gf miscarried so I went down to see her. So that should of not been counted as points because its a family emergency.