By Megan Hickey

CHICAGO (CBS)-– Extreme cold canceled many schools for two days, but in Schaumburg schools were canceled for a third day. This time, it was not just the weather.

District 54 was not able to get the buses up and running, even after the subzero temperatures.

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First Student runs the buses for several districts in the area. A spokesperson said Schaumburg was the only place where the condition of the bus fleet canceled school.

Now parents want to know why.

“We were looking forward to Friday for a return and disappointed when we got the notice that businesses were down, and school was not going to be in session, on Friday,” District 54 parent Chris Tippery said.

School bus operator United Quick Transportation activated subzero weather preps earlier this week, and they were happy to report all of their diesel buses were up and running.

This was also true for fleets of the 16 different transportation companies owned by the Cook-Illinois Corporation, which covers about 200 different school districts in the Chicago area.

“We did our job and our mechanics did their job and we ran this morning and we were very happy and proud about that,” Cook-Illinois Corporation vice president Tom O’Sullivan said.

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Parents in districts like Schaumburg’s District 54, were puzzled when they got the news that the cold weather had rendered about one-fourth of the fleet inoperable and schools would be closed for the approximately 16,000 students in the district.

A spokesperson for First Student, the company that operates the buses, didn’t answer any of CBS 2’s questions about the age of their fleet where the buses are stored or even how many buses they have servicing District 54.

In a statement, the company said they’d been preparing for the extreme temperatures, including having winter teams starting the engines every four hours for 30 minutes at a time and changing the additives in the fuel to prevent freezing.

“However, when there are multiple days of extreme temperatures, mother nature just wins,” the statement read.

O’Sullivan said he can’t speak for any other companies but decades of experience in these cold temps was key for them.

“We were happy that we were able to service the children and our customers,” he said.

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First Student said several other factors came into play in canceling school, including the conditions of the roads and the temperature for students waiting at the bus stop.

Megan Hickey