(CNN) -- One person was killed and four critically injured Tuesday in a series of highway pileups triggered by a dense dust storm on Interstate 10 in central Arizona, a state law enforcement official said.





The dust storm moved through the Pichacho Peak area, about 40 miles north of Tucson, at about 12:15 p.m. (3:15 p.m. ET) and caused "minimal visibility" on a stretch of Interstate 10 there, said Bart Graves, a spokesman for the Arizona Department of Public Safety.





"We have two chain reaction crashes in the westbound lanes," Graves said. "All involve commercial vehicles and passenger cars. There is one confirmed fatality and two additional victims with life-threatening injuries."





Graves said 16 vehicles were involved in the chain reaction accidents at Pichacho Peak.





"We closed the eastbound lanes to allow emergency responders access to the scene," he said. "Due to the poor visibility, all patients were transported by ground ambulance to Tucson area hospitals."





"The dust continues to cause a major hindrance to DPS officers and other rescue personnel," Graves said.





Another pileup, this one involving eight vehicles, occurred about an hour and a half later, 20 miles to the south on I-10, Graves said.





Two people were critically injured in that incident, which occurred on the eastbound lanes of I-10.





Graves said he could not estimate when the interstate would reopen in either direction.





CNN's Tina Burnside contributed to this report.
( CNN ) -- One person was killed and four critically injured Tuesday in a series of highway pileups triggered by a dense dust storm on Interstate 10 in central Arizona , a state law enforcement official said . The dust storm moved through the Pichacho Peak area , about 40 miles north of Tucson , at about 12:15 p.m. ( 3:15 p.m. ET ) and caused " minimal visibility " on a stretch of Interstate 10 there , said Bart Graves , a spokesman for the Arizona Department of Public Safety . " We have two chain reaction crashes in the westbound lanes , " Graves said . " All involve commercial vehicles and passenger cars . There is one confirmed fatality and two additional victims with life - threatening injuries . " Graves said 16 vehicles were involved in the chain reaction accidents at Pichacho Peak . " We closed the eastbound lanes to allow emergency responders access to the scene , " he said . " Due to the poor visibility , all patients were transported by ground ambulance to Tucson area hospitals . " " The dust continues to cause a major hindrance to DPS officers and other rescue personnel , " Graves said . Another pileup , this one involving eight vehicles , occurred about an hour and a half later , 20 miles to the south on I-10 , Graves said . Two people were critically injured in that incident , which occurred on the eastbound lanes of I-10 . Graves said he could not estimate when the interstate would reopen in either direction . CNN 's Tina Burnside contributed to this report .
How many people died  in the Pichacho Peak incident?
How many people died in the Pichacho Peak incident ?
One
One