As children head back to school, safety officials are warning that many Utah schools could fail in an earthquake.

The Utah Seismic Safety Commission says an informal 2006 survey suggests around half of Utah's schools are vulnerable to collapse from a major quake.

The commission and a group of Utah engineers will ask the Legislature in January to fund a comprehensive survey of the condition of Utah's schools.

Lawmakers have rejected the request for two years' running.

Commission chairman Roger Evans says about half of Utah's schools were built before 1975, when many building codes changed to require structural reinforcements.

Evans says some school districts, Salt Lake and Davis among them, have since made a lot of progress shoring up schools.