disaster !!!!

came home to find my 3 girls had fallen over . they look like there dead

i left them on the sill this morning , very small amount of airflow from the top open window , so it could have not been the wind .they where in the sun light all day and it was hot , did the sun kill them ?
did i kill them , i was worried about how little soil there was , and i only lightly watered them every 8 hours or so , they looked fine before i went to work ,
pls someone help me help my girls ,