At least 15 dead in Texas bus crash

<div class="meta image-caption"><div class="origin-logo origin-image none"><span>none</span></div><span class="caption-text">A Sherman police officer stands by as a wrecked bus is taken by on the back of a flat bed tow truck from an accident site early Friday, Aug. 8, 2008, in Sherman, Texas. The crash killed 14, and injured at least 40 more in a group of Vietnamese Catholic worshippers from Houston on their way to an annual pilgrimage at a Missouri church. &#40;AP Photo&#47;Tony Gutierrez&#41;</span></div>
August 8, 2008 6:01:30 PM PDT
Investigators say a blown tire on a charter bus that crashed and killed 15 people had been refitted with a new tread in violation of safety standards. The National Transportation Safety Board also said late Friday that the driver was a 52-year-old who had a commercial license but whose medical certification had expired.

Authorities say the bus was operating illegally earlier in the day when the right front tire blew. The vehicle smashed into a guardrail and tipped over.

Officials say 12 people died at the scene and three others at Dallas-area hospitals.

The bus was carrying a Vietnamese Catholic group from Houston to an annual pilgrimage in Missouri.