ST. JOHN — Social media was abuzz Monday afternoon about a possible blaze at Lake Central High School, but the rumors turned out to be unfounded. 

St. John Fire Chief Fred Willman said crews were dispatched to the school, 8400 Wicker Ave., at about 5:15 p.m. after receiving a call from someone who believed they saw smoke billowing from the school's roof. 

Crews arrived to no fire, but instead vapor billowing from the outdoor air ventilation system that was drawing heat off of chemicals that treat the school's indoor swimming pool. 

The vapor, when met with extreme cold air, appears thicker and mirrors that of smoke, he said. It's similar to when you see steam coming from the dryer vent outside your home, he added. 

As a precaution, fire crews searched the building and checked the fire panels to make sure firefighters didn't miss anything. 

"We had an inclination as to what it was," Willman said. "But we never assume anything. We found it not to be anything faulty or dangerous."

Willman said the vapor will continue but there's nothing to be worried about.

St. John Police Chief James Kveton sent a statement regarding the reports.

"I have received some calls and reports of social media posts regarding a video of a fire at Lake Central High School earlier this evening. These are false reports. Per police officers that were on the scene and the St. John Fire Department this was just vapors from the swimming pool system venting out into the very cold outside air," the statement said.  "This is a vent that regularly operates but produced a more vivid visual effect due to the very low outdoor temperatures. There was no fire found at Lake Central High School."