Leaking propane exploded in a building under construction at Brigham Young University Friday. No one was injured although a resulting fire caused some damage to the building.

Shortly after noon, propane leaked from one of two large propane bottles feeding a heater located in a stairwell in the Joseph Smith Memorial Building at BYU. The propane heater was being used to maintain a warm temperature in the building while concrete work was completed.Propane vapor reached the heater and exploded, said Tom Augustus, captain for Provo Fire Station No. 3.

Augustus characterized the explosion as more a "whoosh" than a "kaboom." Construction crews working in the building had just gone to lunch, and no one was injured by the blast.

The explosion did cause some bracing timbers and plywood used to create concrete forms to catch on fire. That fire was extinguished by the Provo Fire Department before it spread or did much damage, Augustus said.

Damage to the building is estimated at $5,000, although engineers will examine the building to determine whether it experienced structural damage from the explosion.