HOUSTON -- Workers returned to an east Houston refinery Monday where four contract workers were killed when a massive crane collapsed, KPRC Local 2 reported.

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Marion "Scooter" Hubert Odom III, 41, of Highlands; John D. Henry, 33, of Dayton; Daniel "DJ" Lee Johnson, 30, of Dayton and Rocky Dale Strength, 30, of Santa Fe, Texas, died when the 400-foot crane fell at the LyondellBasell refinery in the Houston Ship Channel at about 1:30 p.m. Friday. All were contract workers with Deep South Crane and Rigging.

Seven other contract workers were hurt in the accident.

Relatives were left to wonder how and why their loved ones died.

"The worst part is not really knowing why," one of Johnson's relatives said. "It will definitely affect all of us the rest of our lives. We'll never forget that."

The crane had not been scheduled for anything on Friday, but refinery officials said it was on when it fell. It was capable of lifting 1 million pounds.

Grief counselors were available for workers who need help dealing with what happened. Safety meetings were also scheduled.

A refinery spokesman said the company would address all of the employees' concerns.

The Occupational Health Safety Administration is investigating the collapse.