short of the runway. the canadian equivalent of our n.t.s.b. will lead the investigation. john. >> dickerson: kris van cleave for us in washington. thanks, kris. flames from a series of explosions at a chemical plant in texas are under control tonight. fires have been burning there since wednesday when explosions rocked the facility in port neches, about 90 miles from houston. mandatory evacuations for 50,000 people were also lifted today. officials say initial tests show the air is safe. more to come on the "cbs evening news." the baby boom that set a new record for twins at a missouri hospital. plus, how an n.f.l. star is stepping up to help children who owe money for lunch. and later, the mighty quinn-- now having fun far beyond his window. ugh to quit smoking cold turkey. so chantix can help you quit slow turkey. along with support, chantix is proven to help you quit. with chantix you can keep smoking at first