The layoff was first announced in early June and was scheduled to go into effect Monday morning, leaving 290 workers are on an indefinite layoff.

There were about 1,000 hourly workers at the DMax plant before the layoff was announced, so that means about 30 percent of the workforce is being told to stay home.

The combination of skyrocketing diesel fuel prices and a sharp slump in the sale of large vans and pickups is being blamed for the slowdon that led to the layoffs.

A DMAX spokesperson, Courtney Strickler, said "These volume-related actions were taken to bring production capacity in line with the market demand for heavy-duty full-size pickups."

Strickler said the GM pickup assembly plants in Pontiac and Flint, Michigan are reducing shifts because of the serious slowdown in pickup sales. That means there just aren't as many engines needed.

The layoff announcement is in sharp contrast to the scene five months ago at DMAX. A slick stage show in the plant then attended by Ohio Gov. Ted Strickland and other top officials from GM and Isuzu announced that the plant would be producing the next generation of diesel engine. The announcement even included a promise of 69 million dollars of new capital for a planned expansion for the new line of engines designed to meet tough new emission standards.

Now, all of that hoped-for rosy future is uncertain and the present includes almost 300 workers who don't know when, or if, they'll be called back to the production line.