Utah County Sheriff's Sgt. Spencer Cannon said Monday that results of an autopsy and other forensic testing likely won't be available for three weeks, but that Litizzette's death appears to be accidental.
A press release on Saturday said that some questions surrounding investigation remained unanswered.
"What we're looking for is the direct cause of his death, whether it was the impact of the train, which seems likely, or the 20-foot fall into the river, or drowning," Cannon said Monday.
Meanwhile, the 1,750 students of Mountain Crest High, were dealing with the stunning news that Litizzette repeatedly voted the school's Teacher of the Year by both students and faculty had died.
Principal Bob Henke said the school day was going about as well as it could given the sad circumstances.
"We have extra counselors on hand, and some students have talked with them. Other students have been comforted by our staff," Henke said. "There are a lot of tears being shed, there's a lot of emotion today."
Litizzette taught about 150 students daily at Mountain Crest, and those teens were "pretty quiet and subdued, as you might expect," Henke said.
Many students attended classes Monday dressed in their Sunday's best to honor their departed friend and educator.
Henke said he had lost a good friend. "I've known Larry since he started teaching here 29 years ago. He was loved by everyone, students and staff alike," the principal said.
The Mountain Crest High School Class of 2013's Facebook page noted the tragedy with this post: "RIP, Lit. You will be greatly missed. Thank you for caring about your students and truly making a difference."
Funeral arrangements are pending.