Explosion at northern Mexico steel plant kills 4

An explosion has ripped through a steel plant in northern Mexico and the company says at least four people are dead.
At least 10 other people are recovering from injuries suffered in yesterday's blast.
The Ternium steel company said two workers died at a hospital in the northern city of Monterrey early Tuesday after two died earlier.
The causes of the blast are still being investigated. Monterrey is Mexico's third-largest city and a steel manufacturing hub.