Samsung s4 crushed,how to restart

[AC Question]

Hi. My Samsung s4 mini phone has crashed. It first gave me the message that Whatsapp has an error then my gmail and other apps showed error then my phone finally shut off. It has not switched on since then although it has been put on charge for awhile.

 

[nahoku]

Did the phone crash due to low battery? What was the battery level before it crashed?