Only one of the three lanes in the Montreal-bound Lafontaine Tunnel will be open for most of Friday as repairs continue following an earlier RV fire.

The tunnel was closed at 9:30 a.m. Thursday because the RV caught fire. Two people in the recreational vehicle managed to escape the flames without injury, but the billowing smoke convinced authorities to evacuate the northbound tunnel.

The RV was pulling a trailer with several large propane tanks, which worried authorities because of the possible danger. 

"It's a concern for us, for our security. We approached the vehicle with a lot of water, and seeing what is happening with the propane bottles," said Luc Robillard of the Montreal fire department. 

It took 90 minutes for trapped drivers to begin to leave the tunnel. Transport Quebec closed Highway 20 westbound at the tunnel entrance, leading to a traffic jam that stretched from Ile Charron to Boucherville. Around 3 p.m., Transport Quebec tweeted one lane had been reopened in the tunnel on Highway 25 northbound, heading into Montreal.

All three lanes in the tunnel will reopen for the Friday morning rush hour between 5:30 a.m. and 9 am. At 9, two lanes will once again be closed to let workers replace 3,000 metres of electric cables damaged by the fire. It’s not known how long the repairs will take to complete.

The cause of the fire is not known, but police have determined it started at the front of the RV.