It happened around 1:50am at the Northwest Medical Center on FM 1960 near Cali. There were about two dozen people in that area of the building at the time.
"We were all sitting down in the lobby area. My cousin said she smelled some smoke, so we all started smelling it," said witness Kevys Watson. "Next thing I know, there was smoke coming out of the vent right when you walked in."
Fire officials believe they know what caused the problem.
"On arrival, we investigated and found that there was an air handling unit causing the smoke," said Deputy Chief Scott Windisch with the Ponderosa Fire Department. "At this time, the air handling unit has been disabled and smoke has been depleted."
Officials are now using a large volume fan to clear out the emergency room.
There were no reported injuries.
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