The daily Blick set the tone, with a big black cross on the front page.
The mass circulation newspaper said words could not express the pain of the victims' families, noting that Tuesday, March 13th, when the accident occurred, would be "a black day for the history of our country."
Le Matin wrote that "they should have gone home yesterday," but instead the children's parents had to come to Switzerland to retrieve the injured ones or to identify the victims' bodies.
The newspapers also raised questions about the 100-kilometre (60-mile) speed limit inside the tunnel and the design of the emergency stop area where the fatal crash occurred.
Geneva-based Le Temps asked, "Will the speed limit be lowered for heavy vehicles or will the design of the emergency stop areas be modified?"
A spokesman for the federal roads service (Ofrou) did not rule out that the accident would lead to a re-think about the right-angle shape of the spots where vehicles can pull over in an emergency.
"For the moment, the emergency stop areas have this shape as called for by regulations," said Antonello Laveglia.
"It's clear that with what has happened, it's not ruled out that something will be re-discussed or changed," he said. "The accident is an occassion to think further on this topic."
The Zurich daily Tages-Anzeiger said that the design of the emergency area was common in Swiss tunnels, but said that this could be re-visited as "due to that wall, a collision has occurred."
The bus had entered the motorway tunnel which has a speed limit of 100 kilometres per hour and, for reasons still unknown, it hit the curb on the right side of the roadway and struck the emergency stop's concrete wall head-on.
The 2.5-kilometre Sierre tunnel was built in 1999 and has the most modern ventilation standards, emergency exits, signaling and energy supply and conforms with all safety regulations, Laveglia said.
The coach, which was carrying 52 passengers, was travelling from the Val d'Anniviers ski resort towards the Swiss town of Sion on the A9 motorway when the accident happened at 9.15pm Tuesday (2015 GMT).