Minnesota State Patrol Capt. Matt Langer said Thursday it is too early to speculate about the cause of the tour bus crash Wednesday on Interstate 90, in which two people died and 21 were injured.

During a press conference at the Minnesota Department of Public Safety headquarters in St. Paul, Langer said the State Patrol will continue its crash investigation, which will likely take several weeks to complete.

“Investigations like this case take a great deal of time to complete given the number of people involved and the intricate nature of conducting a thorough post-crash commercial vehicle inspection of the motor coach involved in this crash,” Langer said.

It wouldn’t be uncommon for the investigation to last several weeks or even several months, he said.

The crash took place at 3:09 p.m. Wednesday three miles west of Austin. The bus, of Strain Bus Line Motorcoach Tours of Rochester, landed on its right side after crossing a grassy median and somehow avoided oncoming traffic on Interstate 90 three miles west of Austin, according to the Minnesota State Patrol.

It was headed back to Rochester following a day trip to Diamond Jo Casino in Northwood, Iowa, according to a Strain representative.

Though the State Patrol cannot speculate as to the cause of the crash this early in the investigation, one factor being considered is whether the driver, Ed Erickson, 52, of Elgin, suffered a “medical episode” while behind the wheel, a press release states.

“We’re aware of the media reports saying that the driver of the bus suffered a medical episode,” Langer said. “Standing here today, I’m unable to discuss details about that other than to say that we’re aware of it. His medical condition and any medical episode suffered at the time of the crash is just one of many things we’re looking at in trying to determine what caused this collision.”

The Rochester Post-Bulletin reported Thursday morning that Erickson suffered a ruptured aneurysm in his chest.

Langer said the focus of the State Patrol’s investigation Thursday was to speak with everyone on board the bus and any witnesses to the crash. They are also beginning the commercial vehicle inspection effort on both the bus and the bus company.

The casino trip takes place every Wednesday, picks up passengers at Rochester and surrounding areas in the morning, arrives at the casino around 11 a.m., then heads back after roughly four hours at the casino.

Kim Pang, general manager of Diamond Jo Casino released the following statement Thursday morning:

“Strain Motorcoach has traveled from Rochester, Minnesota to the Diamond Jo every week for more than a year. When we hear about tragedies like this it’s heartbreaking, but when it hits so close to home, to our friends, it’s devastating. We will continue to keep the driver, passengers, their friends and family in our thoughts and prayers.”