The vacant building collapsed Friday morning, spilling a mound of debris into a street in downtown Sioux Falls. The cause of the collapse is not yet clear.
Fire Rescue Chief Jim Sideras says one person trapped in the debris has been talking on the phone with her mother as crews try to reach her. Sideras says she can't see daylight so rescue workers know she's completely covered by debris.
Sideras says that the other person trapped is a construction worker.
The building has been vacant since September and was expected to reopen in the spring as a drug store.
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