Officials say an explosion at a home in south Regina and basement fires at two other houses in the neighbourhood were caused by leaking natural gas that had built up underground.

The gas line rupture was found near 37 Woodlawn Place. Investigators have determined the gas travelled underground before igniting at three homes in Whitmore Park earlier this week.

Damage to the home that was completely destroyed by the explosion and ensuing fire on Monday is estimated at $400,000.

The attic of a neighbouring home at 1008 Shannon Road suffered an estimated $100,000 in damage.

A basement fire at 27 Norris Road caused an estimated $100,000 and a similar incident at a home at 1000 Shannon Road on Sunday.

The early morning explosion sent two people two hospital, one of them with serious injuries.

About 25 homes in the area were evacuated, and natural gas service was shut off at just over 60 homes.

Residents began returning to their homes around 3 p.m. Monday after power and gas were restored to the area.

SaskEnergy says the spring thaw could have contributed to ground shifting, which may have caused the line to break. 

Photo gallery: Home Explosion in South Regina