It is common practice to disable ping (ICMP echo response) in servers and hosts, so that would imply the threat exists.

http://admin.utep.edu/default.aspx?tabid=53710

This is kind of DOS attack which is traditionally very old and outdated. 

A single user with ping flood or ping of death cannot take a server down. It needs to be multi threaded or massive co-ordination of attackers should be playin with single server for slight possible chance. However the operatin system and security devices have built in security features to disable the ICMP requests. Hence ping flood does not have much impact these days.

Hope this helps!!

thankyou very much for answers.