Roofing crews are among the workers being recruited away from central Oklahoma builders by out-of-state contractors as work abounds to repair damage from May tornadoes, according to observers. Construction crews may be offered bonuses and pay raises by new players in the region, which builders said is leading to a shortage of laborers. "Labor is really difficult right now. People are losing their crews. Not until after the tornadoes did it hit us," said Robert Crout, president of the Central Oklahoma Home Builders Association.