DON'T KNOW THE EXTENT OF THE INJURIES. THE PROFESSOR WAS PREPARING THE SOLUTION FOR A LAB LATE YESTERDAY AFTERNOON WHEN IT CAUGHT FIRE. THE LAB WAS NOT PERMANENTLY DAMAGED AND THE BUILDING WAS BACK OPEN TODAY. >>> A FIRE ON THE ROOF OF JEFFERSON HOSPITAL PROMPTED A LARGE EMERGENCY RESPONSE TODAY. THE CONSTRUCTION FIRE SEND SMOKE TO THE UPPER FLOORS THROUGH THE HVAC SYSTEM. SHELLEY BORTZ WAS THERE SHORTLY AFTER THE FIRE BROKE OUT. >> WE SPOKE TO HOSPITAL OFFICIALS ABOUT AN HOUR AGO. THEY CONFIRMED TO US NORMAL OPERATIONS HERE AT THE HOSPITAL HAVE RESUMED. THEY ALSO TELL US, MOST IMPORTANTLY, THAT PATIENT CARE WAS NEVER AFFECTED WHILE CREWS WORKED TO CONTAIN THE FIRE. >> AT FIRST, BECAUSE WE DROVE AN HOUR AND A HALF TO GET HERE. >> Reporter: SHORTLY BEFORE 11:30 THIS MORNING, THE CALL CAME IN FOR A SMALL CONSTRUCTION FIRE ON THE ROOF OF JEFFERSON HOSPITAL, LOCATED ON COLE VALLEY ROAD. THE THREE ALARM FIRE PROMPTED EMERGENCY CREWS FROM MULTIPLE FIRE DEPARTMENTS ACROSS THE AREA. AT THE SAME TIME, PATIENTS WERE SHOWING UP AT THE HOSPITAL FOR SCHEDULED APPOINTMENTS. >> WE WENT TO TURN IN AT THE MAIN ENTRANCE THERE AND THERE WAS A SECURITY GUY THERE. HE RAN OVER, NO YOU CAN'T GO UP. WE HAD NO CLUE WHAT WAS GOING ON. >> Reporter: OFFICIALS SAY, INITIALLY BECAUSE THERE WAS A FIRE IN THE HOSPITAL, EMERGENCY SERVICES CALLED FOR A MASS CASUALTY INCIDENT OUT OF AN ABUNDANCE OF CAUTION. THIS IS STANDARD PROCEDURE, THEY SAY, IN THE CASE A LOT OF PATIENTS NEEDED TO BE MOVED TO TWO OTHER MEDICAL FACILITIES. CREWS WERE ABLE TO CONTAIN THE FIRE QUICKLY, SO THE NCI WASN'T NEEDED. >> TO MY UNDERSTANDING, IT WAS SOME WELDING GOING ON, CUTS AND INSULATION ON FIRE AND THAT SPREAD. THAT CAUSED SOME SMOKE TO GO THROUGHOUT THE BUILDING. MOST OF WHAT WE WERE DEALING WITH TODAY IS , AS YOU MENTIONED, SMOKE FUMES. >> Reporter: SMOKE ENTERED THE UPPER FLOORS THROUGH THE AIR HANDLING SYSTEM BUT WE ARE TOLD PATIENT CARE WAS NOT AFFECTED. AS A PRECAUTIONARY MEASURE, THE HOSPITAL DIVERTED PATIENTS FROM ITS EMERGENCY DEPARTMENT TEMPORARILY. THAT DIVERSION HAS SINCE BEEN LIFTED. >>> HOUR FIRE MARSHAL'S OFFICE HAS COME AND DONE AN INITIAL ORIGIN AND CAUSE AND THAT WAS DETERMINED TO BE ACCIDENTAL. >> Reporter: THOSE PATIENTS WE TALKED TO TODAY WERE ABLPOE INT MAKE