UPDATE — Jan. 24, 2020: A statement from the Ministry of Transportation says contractors have secured one lane of the highway at Kennedy Hill. Passenger vehicles or light pickups will be permitted to travel between noon and 8 p.m. Friday. The route will be closed indefinitely after 8 p.m. as workers begin installing a portable bridge.

Tofino, Ucluelet and surrounding communities have been cut off from the rest of Vancouver Island because of what DriveBC is calling a "major road failure" caused by a rock blast that damaged Highway 4.

The Ministry of Transportation and Infrastructure says the highway will remain closed all evening and there is no estimated time of reopening.

According to Tofino Mayor Josie Osborne, the overnight blasting was part of a major highway improvement project.

"The rock that came down on the road compromised an existing retaining wall along the edge of the highway. Then a section of the road failed, so they've lost the travel lane," said Osborne.

Crews have started excavating the damaged area and replacing the road surface after a geotechnical assessment determined the area was safe.

According to DriveBC, the closure is 14 kilometres east of the southern boundary of Pacific Rim National Park, where the highway runs beside Kennedy Lake.

The plan is to fix the highway by excavating the damaged roadbed and replacing it with a new surface, said Ministry of Transportation and Infrastructure spokesperson Danielle Pope.

Rock fill for the embankment is being hauled in and placed to build up the damaged road.

Crews will work around the clock to reconstruct and stabilize the slope and fix the road as quickly as possible, Pope said.

First responders and emergency vehicles can be accommodated through the area if necessary, she said.

Osborne says it's important to note that air evacuation is an option for residents in the case of a major emergency.

"There are protocols in place between the ambulance service, the ministry and the contractor doing the work, so, in the event of life-threatening emergency, there are ways to get people out of here," she said.

Travellled through the rainstorm to make it home last night - now the world is cut off from us. <a href="https://twitter.com/hashtag/BCHwy4?src=hash&ref_src=twsrc%5Etfw">#BCHwy4</a> is closed ‘til 5pm due to rock on the road at Kennedy Hill - please follow ⁦<a href="https://twitter.com/DriveBC?ref_src=twsrc%5Etfw">@DriveBC</a>⁩ and visit <a href="https://t.co/927IbuvL8y">https://t.co/927IbuvL8y</a> for updates. <a href="https://twitter.com/hashtag/tofino?src=hash&ref_src=twsrc%5Etfw">#tofino</a> <a href="https://twitter.com/hashtag/ucluelet?src=hash&ref_src=twsrc%5Etfw">#ucluelet</a> <a href="https://twitter.com/hashtag/portalberni?src=hash&ref_src=twsrc%5Etfw">#portalberni</a> <a href="https://t.co/lmQu4XsOJa">pic.twitter.com/lmQu4XsOJa</a> —@Josie_Osborne

Information stations have been set up at Sproat Lake to the east, and at the junction of Highway 4 and the Tofino-Ucluelet Highway to the west, to let travellers know about the closure.

"So, people will know they have to wait in Port Alberni or wait on the west coast before they can go through," Osborne said.

"If you're trying to reach an airport after visiting Tofino or Ucluelet, or if you're trying to get home or wanting to go out for a doctor's appointment, it's a big inconvenience."

According to Osborne, the Highway 4 improvement project is one of the largest ever undertaken in the province in terms of how much rock is being moved. Crews are widening the road to make it safer.