At least six people were injured after a house explosion Sunday morning in Austin, Texas, leveled one house and severely damaged another, according to the Austin Fire Department.

A "substantial" propane gas leak led to a powerful explosion earlier this week that injured six people, destroyed a recently finished northwest Austin home and damaged others nearby, according to the Travis County Fire Marshal's Office.

The fire marshal also confirmed two people injured in Sunday's explosion remain in critical condition as the investigation enters the final stages.