I studied too many derailments involving HAZMATs to have stuck around like that... There's no telling what is involved, and being in SE Texas, the chemical coast offers plenty of dangerous varieties! There's nothing in the NTSB page about this derailment. No preliminary reports, not even an overview. I wouldn't expect a full report for 2-4 yrs.
Some of their annual reports on the various Class I, II, III financials don't even start coming out until 8-9 (August-September) months after the prior year ended.