A relatively small fire sent a large amount of smoke into the air Thursday afternoon in central Waterloo.

Fire crews were called to an under-construction apartment building at 339 King Street North, between University Avenue and Columbia Street, shortly after 2:30 p.m.

A boom truck, a machine used to lift workers and tools, had caught fire behind the construction site.

Although the truck was engulfed in flame and smoke was visible from as far away as downtown Kitchener, the fire was contained to the truck and some small pockets of debris and did not extend to the building itself.

“Thank goodness it happened during the day (and) we had lots of construction crews on scene,” said John Percy of the Waterloo Fire Department.

Fire officials noted that the propane used to operate the truck was feeding the fire, making it more difficult to extinguish.

There was no damage to the building under construction. No injuries were reported.

King Street was closed between University and Columbia until shortly after 5 p.m.