GULF SHORES, Ala. — A 73-year-old Fairhope, Ala., man accelerated just before his SUV plowed into the Gulf Shores High School Band during its annual Mardi Gras parade, injuring 12 students, with four in critical condition.

The band members are between 12 and 17 years old. Eight were taken to a South Baldwin Medical Center, three patients to Pensacola hospitals and one to USA Medical Center in Mobile, Ala.

“Every indication is that it did not involve drugs or alcohol, nor is there any indication it was intentional,” said Gulf Shores Police Chief Edward Delmore. “It was a tragic accident by an elderly individual.”

The driver is voluntarily undergoing testing and does not appear to have suffered injuries.

“He is aware there was an incident,” Delmore said.

The vehicle came to a rest on top of several of the students.

The accident happened at the beginning of the parade about 10 a.m. Tuesday, as it turned onto Highway 59. There were an “incredible amount of resources” on the scene immediately, according to law enforcement.

An Alabama state reconstruction team has been brought in to determine how the accident happened, and is gathering evidence and witness testimony as well as examining the vehicle that plowed into the students.

“Our primary concern is with the students and how they are doing,” said Baldwin County Sheriff Huhey Hoss Mack, in a live interview on WPMI-TV in Mobile. “Secondary, everyone wants to know how this could have happened.”

Three hours after the crash, dozens of police officers and police vehicles remained on the scene, using neon-colored spray paint to mark the road. Officials blocked off Highway 59 in both directions.

Local law enforcement were contacted shortly after the accident by the FBI and Homeland Security, but because the crash did not seem intentional, federal assistance wasn't needed, Mack said.

Longtime Gulf Shores resident and business owner James Schwartz was preparing to watch the parade with his family when the crash happened.

"I'm glad that they went ahead and canceled the parade. It is a tragedy," Schwartz said Tuesday as he watched police collect beads, feather boas and other no-longer-festive items from the road.

Schwartz, who owns Hazel's Nook restaurant, said the annual parade is a major event in Gulf Shores.

"The kids get out of school and lots of people come out for it," he said.

The Alabama crash is the second in less than a week involving a Mardi Gras crowd. Late Saturday, a pickup plowed into a crowd watching the parade of the Krewe of Endymion, injuring 32 people. New Orleans police said the driver, 25-year-old Neilson Rizzuto, had a blood alcohol level nearly three times the 0.08 legal limit.

Rizzuto was booked into the Orleans Justice Center jail Sunday on two counts of first-degree negligent vehicular injuring, one count of hit-and-run driving causing serious injury and one count of reckless operation of a vehicle. More charges could be pending.