Complex sentence: According to locals, at this point the U.S. military fired upon the unarmed crowd, killing 17 and wounding more than 70 of the protesters while the U.S. suffered no casualties from the incident.
Split into simpler sentences: According to locals, at this point the U.S. military fired upon the unarmed crowd. Reportedly, 17 protesters were killed while the U.S. suffered no casualties from the incident.