WASHINGTON, Aug. 2 (Xinhua) -- A school building in the midwestern U.S. state of Minnesota collapsed after a natural gas explosion Wednesday, leaving two people still unaccounted for and one critically injured, authorities said.
Fire crew of the Minneapolis Fire Department were searching for possible victims in the debris and trying to extinguish a blaze following the explosion-led collapse at Minnehaha Academy's upper school in Minneapolis, near the Mississippi River.
Assistant Fire Chief Bryan Tyner said fire crew rescued three people off the roof and were looking for two others who were unaccounted for.
He said a third person believed to be missing was found outside the building and uninjured.
The two others still missing were a subject to a "search and rescue mission," but they might actually not be inside the building, said Tyner, adding it may take a while to figure that out.
Police said five people were hospitalized and one of them was in critical condition. All of them were adults.
The fire department initially reported one person was killed, but later said the fatality was "not confirmed" in a tweet.
Video footage online showed smoke rising from the debris amid flames.
In a statement, the academy said the explosion involved a natural gas leak, but it only affected the upper school. It also has a lower school, many blocks downriver.
Founded in 1913, Minnehaha Academy is a Christian school, which had over 800 students enrolled during the 2015-2016 school year, with the upper school housing grades 9-12.
The 2017-2018 school year is scheduled to begin on Aug. 23, but there were students, teachers and coaches at the school for sport training, summer school and other activities.
A school official said about a dozen students in the school gym were all OK.
