The bed is so dry

Tom went swimming in the lake with his friend Tim.  They found a big rock so they jumped in the water, but unfortunately, he didn’t look at the water first. There was no water and he was realy hurt. Tim tried to warn him but he was a bit deaf so he couldn’t hear him. Tim had never seen the river bed so dry.  Then Tom said hes ok  and he will look next time.  So the next day, they went again and he looked and there  was water this time!  Tim said maybe the river flooded in from the sunset.