UPDATED
As of 12:45, all systems have been returned to normal, and normal operations may resume.
At approximately 10:45 am the exhaust system serving the 4th floor experienced a failure. The backup system worked as expected, returning the room pressures to normal. During the above-noted times facilities technicians will be troubleshooting the cause and making repairs, if possible, to the exhaust system. During this time NO work shall take place in any BSL3 lab on the 4th floor.