Abstract: EMPLOYEES #1 AND #2 WERE TAKING A WATER SAMPLE FROM A MANHOLE AT A WASTEWATER TREATMENT PLANT. EMPLOYEE #1 HAD ENTERED A MANHOLE EARLIER IN THE DAY TO TAKE A SAMPLE SO EMPLOYEE #2 AGREED TO ENTER THE SECOND MANHOLE. A THIRD EMPLOYEE (EMPLOYEE #3) ENTERED THE AREA JUST AS ENTRY INTO THE MANHOLE BEGAN. SHORTLY AFTER EMPLOYEE #2 ENTERD THE MANHOLE, EMPLOYEES #1 AND #3 HEARD A SPLASH. THE OTHER TWO EMPLOYEES ENTERED THE 10 FEET DEEP, 5 FEET WIDE MANHOLE AND DISCOVERED EMPLOYEE #2 UNCONSCIOUS AND LYING FACE DOWN. EMPLOYEE #3, ORDERED OUT OF THE MANHOLE BY EMPLOYEE #1, MANAGED TO MAKE IT OUT BUT BRIEFLY LOST CONSCIOUSNESS AT THE TOP. WHEN EMPLOYEE #3 BECAME FUNCTIONAL AGAIN, HE SAW THAT BOTH OF THE OTHER EMPLOYEES WERE LYING FACE DOWN. HE RADIOED FOR HELP. ANOTHER EMPLOYEE ATTEMPTED A RESCUE BUT HAD TO GIVE UP THE ATTEMPT WHEN HE DISCOVERED THAT THE SCBA HE WAS USING HAD BECOME DAMAGED UPON ENTRY. RESCUE WAS EVENTUALLY ACCOMPLISHED BY THE FIRE DEPARTMENT. ALL THREE EMPLOYEES WERE HOSPITALIZED. EMPLOYEES #1 AND #2 DIED WHILE EMPLOYEE #3 WAS TREATED FOR HYDROGEN SULFIDE POISONING. . AN ATMOSPHERIC TEST DONE BY THE EMPLOYER ON THE DAY OF THE ACCIDENT SHOWED AN OXYGEN LEVEL OF 5%. TESTS DONE A DAY LATER BY OSHA SHOWED AN OXYGEN CONTENT OF 11%. IT IS SUSPECTED THAT BACTERIA IN THE WATER IN THE MANHOLE MAY HAVE BEEN RESPONSIBLE FOR REMOVING THE OXYGEN FROM THE MANHOLE ATMOSPHERE.