( CNN ) -- Two tractor-trailer trucks crashed and burst into flames Thursday on a bridge between the United States and Mexico , shutting a key border crossing and killing four people , police said . Police look at the aftermath of a fiery crash on a bridge linking Reynosa , Mexico , and Pharr , Texas . The collision on the Pharr-Reynosa International Bridge in Texas triggered a chain-reaction accident with three other vehicles , said Lt. Lupe Salinas with the Pharr Police Department . A pickup flipped off the bridge , killing three people . Another person died in a vehicle that struck one of the tractor-trailers . Six others were injured . Pharr Emergency Management Coordinator Elsa Sanchez told The Associated Press the pickup truck had Texas license plates , and the two 18-wheelers and a minivan involved in the wreck appeared to have Mexican plates . Watch aftermath of fiery crash » . The accident happened around 7:30 p.m. ( 8:30 p.m . ET ) . The bridge was closed for the rest of the evening . The bridge reopened on Friday morning after Texas Department of Trnasportation engineers inspected it , according to CNN affiliate KRGV . The bridge is normally open from 6 a.m. until midnight and is closed overnight . The 3.2-mile-long bridge connects U.S. 281 in Pharr , Texas , to the city of Reynosa in the Mexican state of Tamaulipas , according to the city of Pharr 's Web site . On an average day , the site says , 5,800 vehicles cross it . E-mail to a friend . CNN 's Ed Payne and Jessica Jordan contributed to this story . Copyright 2008 CNN . All rights reserved.This material may not be published , broadcast , rewritten , or redistributed . Associated Press contributed to this report .
NEW : Bridge reopens Friday morning after highway engineers give OK . Four killed in chain reaction crash that started when two tractor - trailers collided . Three killed in pickup truck that fell off bridge ; 4th victim in car that hit one 18-wheeler . # ##es on bridge between Houston , Texas , and Reynosa , Texas .