OSHA says it could be months before it figures out exactly what happened at an Omaha, Neb., Wal-Mart construction site Sunday where one worker was killed and another critically injured, according to KPTM.com.

Police say 34-year-old Jose Sanchez of Texas died and 21-year-old Luis Alejuandro Azeona Rocha of Mexico was injured, when the ironworkers fell onto some metal around noon Sunday. The two men fell 25 feet, according to Graham Construction.

Graham Construction is building the store, but the two injured men were subcontractors for a Texas-based company, D&BR Building Systems.

"They target Wal-Marts and go from state to state," said Scott Fowler of Graham Construction.

Investigators from OSHA spent Monday looking for any hazardous conditions that may have contributed to the accident.

"It's a risky business, but yet we mitigate risks and we have plans to avoid risks and we have to review and make sure everything is right," Fowler said.