Michoacán Gov. Silvano Aureoles initially said Tuesday that the helicopter was shot down, but later said the cause was under investigation.
The Mexican crashed out in Melbourne, the season-opening race on March 20, after a collision with Fernando Alonso who was trying to overtake but instead rammed into the rear of the Haas.
A passenger van crashed into a trailer truck.
Dozens were taken to the hospital, according to the police.
Both lanes are blocked.
Three vehicles were involved in the incident, which left seven injured.
The accident involved motorcycles, cars and heavy trucks.
A truck with Arizona plates was involved in the incident.
The 24-year-old woman suspected of plowing a car into pedestrians on the Las Vegas Strip is on suicide watch.
The two trailers crashed on the Ciudad Victoria-Soto la Marina road.