ON 1/16/06 EMP FIRST REPORTED TO SUPERVISOR THAT HE WAS EXPERIENCING DISCOMFORT WHICH HE BELEIVED WAS RELATED TO AN INCIDENT THAT OCCURRED THE PREVIOUS WEEK. HE WAS CHANGING A FITTING FOR THE HOSE ON A PORTABLE SUMP PUMP AND WHILE HOLDING THE PUMP IN A BEAR HUG, HE FELT PAIN ACROSS HIS CHEST.