State and federal officials continue to investigate the reason behind a deadly blast earlier this month at the Williams Companies plant near Gonzales.

Officials say they plan to inspect a key element of the facility this week that one federal investigator says failed catastrophically.

Investigators say they hope to be able to fully examine the facility's heat exchanger in the propylene fractionation unit.  That part of the facility is where company officials believe was near the explosion and fire.

Two workers died, and two workers remain hospitalized after the blast.

Williams company spokesman Tom Droege says the the company is cooperating with state and federal officials.