VICKSBURG, Miss. (May 22)—Two more employees of Rouse Polymerics Inc. have died from burns suffered in a May 16 explosion and fire at the plant. Tywayne Croskey, 25, died the evening of May 21, and Alfred Harrison, 42, died at 12:30 a.m. May 22, according to Rouse Polymerics CEO Michael Rouse. Clyde "Teddy" Smith, 40, died May 17, the day after the explosion in the facility's packaging area. Of the other nine seriously injured workers, two have been released from the hospital and a third may soon be, Rouse said. Authorities still are not sure what caused the explosion, but they know it didn't occur in the plant's fine-grind technology area, he said. "I don't know how this could have happened," Rouse said. "I've been in business 14 years, and safety has always been my No. 1 priority. We had sprinklers and monitors throughout the plant."