This extremely large and destructive tornado caused mass destruction in Broken Arrow, Oklahoma...this tornado was a part of a line which occurred during a much larger outbreak, this tornado was the first of 3 EF5 tornadoes that touched down during the outbreak...the Tornado first touched down as a weak EF0 about 25 miles southwest of Broken Arrow at 1:03PM...by 1:05PM the Tornado strengthened to a EF1 tornado...by 1:08PM the strengthening tornado strengthened to a strong EF2 tornado...and continued to strengthen...the tornado started to cause EF3 damage at 1:12PM...the Tornado already was a EF4 by 1:13PM...the Tornado reached EF5 intensity by 1:26PM...the Tornado struck the city of Broken Arrow at 1:36PM...the Tornado weakened to a EF4 tornado at 1:40PM...the Tornado roped out 16 minutes l