Students at Estabrook Elementary School were evacuated from the building Thursday morning, after a heating and cooling issue caused a water line to break.

Officials with the Ypsilanti Fire Department said an air chiller motor in the school's air conditioning system overheated, causing the water line to burst. Firefighters said water was flowing out from the inside of the air-conditioning unit.

School officials said the district's maintenance crew is cleaning up from the water mess.

The incident occurred at about 11 a.m., and the majority of students were given the "all clear" to return to the school safely around 11:30 a.m.

School officials said during the evacuation, staff walked the elementary students around the corner and down the street to Ypsilanti Middle School, which had a half-day Thursday.

Fourth- and fifth-grade students had to remain at the middle school through their lunch period so staff could clean their wing of the elementary, which saw the most water as it was where the heating and cooling issue occurred, school officials said.

Danielle Arndt covers K-12 education for AnnArbor.com. Follow her on Twitter @DanielleArndt or email her at daniellearndt@annarbor.com.