The world's busiest land port crossing, at San Ysidro, Calif., reopened its 24 northbound travel lanes from Mexico on Sept. 18, five days after a 50-ft by 50-ft temporary wood platform, meant to catch demolition waste on a $577-million border station renovation, collapsed and rained heavy debris on vehicles and personnel. One construction worker was seriously injured, and 16 other people also were hurt, including three laborers. Concrete, metal supports, wooden planks and a large black tarpaulin damaged 15 vehicles. Rescuers extracted three people from the wreckage.

Miller Environmental Inc., Anaheim, Calif., was removing plaster from an administration building set for demolition when the platform structure under the roof fell, showering debris across eight northbound lanes. Mller was a subcontractor to Hensel Phelps Construction Co., Greeley, Colo., which is managing the upgrade to the 30-year-old border crossing facility, which handles 50,000 northbound cars and 90,000 pedestrians daily.

The three-phase project, which broke ground in February, will expand border facilities to 227,000 sq ft on 50 acres and realign and widen a portion of Interstate 5. Federal officials are investigating the collapse, whose cause is still unknown. Miller Environmental was fined $18,400 for a safety violation that occurred last year on a separate project. U.S. officials say the mishap is not expected to delay project completion, which is set for mid-2016.