A house exploded before dawn Thursday in South St. Paul, and officials are saying at least two people are feared dead.

The blast in the 1200 block of S. 9th Avenue lit the dark sky a bright orange and sent grayish smoke skyward high enough to be captured on multiple traffic cameras along Interstate 494.

The explosion occurred about 6;18 a.m., the flames were quickly extinguished, and fire crews were still on the scene hours later, said South Metro Fire Chief Mark Juelfs.

Juelfs said firefighters quickly extinguished the flames and have been going through the debris searching for the victims inside the residence, where vehicles were parked outside.

The chief said it was too early to offer a preliminary indication of what set off the blast.

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