HOUSTON (AP) — Federal safety experts say errors by a Houston Ship Channel pilot likely caused the 2015 collision between two 600-foot vessels that led to a chemical spill.

The Houston Chronicle (http://bit.ly/28ngTYF ) reported Wednesday that the National Transportation Safety Board has urged Houston officials to improve channel safety — especially during heavy fog.

The report called on Houston pilots to emphasize better bridge management and more timely communication.

The NTSB concluded that the pilot's failure to communicate as he guided the Conti Peridot through thickening fog contributed to the collision with an outbound chemical tanker, the Carla Maersk.

The March 9, 2015, accident caused about 88,000 gallons of a flammable chemicals to spill. Nobody was hurt.

A spokesman for the Houston Pilots Association welcomed the recommendations and said the report will be reviewed.