Minnehaha Academy in south Minneapolis has submitted preliminary plans for rebuilding its upper campus after a catastrophic natural gas explosion last August that killed two people.

A proposal to be reviewed by the city’s planning commission this week would construct two additions to the existing north campus at 3100 West River Parkway, totaling about 100,000 square feet. The campus will have capacity for more than 700 middle school and high school students, according to a staff report.

The plan will be heard by the planning commission’s committee of the whole on Thursday, a precursor to a public hearing before the commission on April 9.

The upper school, which has more than 350 students, has been moved temporarily to a former college campus in Mendota Heights.

In a blog post on the school’s website in February, school leaders said they plan to open the new site by the start of the school year in fall 2019.

The explosion killed a receptionist and custodian and injured nine people. A lawsuit filed by relatives of one victim last fall blamed the explosion on mistakes by CenterPoint Energy and a contractor, Master Mechanical. The suit is pending.

The National Transportation Safety Board is still investigating, and it could take a year or more to complete the probe, NTSB spokesman Terry Williams said Monday.

Eric Roper