He said excavations were a leading cause of pipeline accidents.

Integrity Management Programs have led to a reduced amount of pipeline accidents.

The blast that killed his brother and five other workers was the latest in more than 12 pipeline accidents to befall Pemex since October.

This was the deadliest gas transmission pipeline accident in US history.

Records from the Federal Department of Transportation, for example, show that 21 people died in pipeline accidents in 1995, compared with 41,000 on highways nationwide.

Fatal pipeline accidents, however, are rare.

In 1991 pipeline accidents caused 14 deaths, including 8 on a fishing boat that strayed outside a marked channel and hit a pipeline in shallow water.

According to records from the Federal Department of Transportation, 21 people died in pipeline accidents in 1995, as opposed to 41,000 on the nation's highways.

In a 1996 follow-up report on several pipeline accidents, the safety board said the number of such incidents had remained constant since 1986.

"This much-needed action comes on the heels of several major pipeline accidents over the past several years."