A pedestrian is in critical condition after a two-vehicle crash involving an Ottawa Fire Services SUV at Baseline Road and Fisher Avenue during the morning rush hour.

The woman in her 40s was rushed to the trauma centre of the Ottawa Hospital's Civic Campus with life-threatening injuries and multi-system trauma, said Marc-Antoine Deschamps with the Ottawa Paramedic Service.

Baseline is closed in both directions from Merivale to Prince of Wales Drive, while Fisher is closed in both directions from Trent Street to Dynes Road.

Try to avoid even coming towards the road closures. Find alternate routes well before!!!! Traffic is extremely congested in the surrounding area!!!<a href="https://twitter.com/hashtag/otttraffic?src=hash&ref_src=twsrc%5Etfw">#otttraffic</a> <a href="https://twitter.com/hashtag/ottnews?src=hash&ref_src=twsrc%5Etfw">#ottnews</a> <a href="https://t.co/JXoIPKK5QT">https://t.co/JXoIPKK5QT</a> —@carbinekane

Two other people in the vehicles — one of which is an Ottawa Fire Services commander vehicle — were taken to hospital with minor injuries from the crash, which happened at about 7:45 a.m.

One was a man in his 30s and the other a man in his 50s.

Ottawa Fire Services referred questions about the crash to the City of Ottawa. Neither Ottawa police nor the City of Ottawa would say whether the fire services SUV had its emergency lights activated at the time of the collision, citing the ongoing investigation.

The city's fleet services safety branch reviews "all collisions involving City-owned vehicles," director Donald Dinelle wrote in a statement to CBC News. That review isn't expected to happen until after the police finish their investigation into the crash.