Ottawa paramedics say a pedestrian and a cyclist suffered serious injuries after being struck by vehicles in separate collisions in Ottawa’s south end on Tuesday afternoon. Paramedics spokesperson Marc-Antoine Deschamps says first responders were called to Fairbanks Avenue and Crestview Road in Alta Vista at approximately 2:10 p.m. for a collision between a pickup truck and a cyclist. A 90-year-old man riding the bike was transported to hospital in critical condition, paramedics say. The driver of the vehicle was not hurt. The Ottawa Police Service is asking anyone who witnessed the incident or has dash-camera footage of the collision to contact officers in the Fatal Collision Investigation Unit at 613-236-1222, ext. 2345. At around the same time, paramedics were called to Earl Armstrong Road and Canyon Walk Drive in Riverside South after a pedestrian was struck by a vehicle. A man in his late teens was taken to hospital in serious condition. His injuries are not life-threatening, paramedics say. Ottawa police say an investigation into both collisions is ongoing. The two incidents come after a 23-year-old woman suffered life-threatening injuries after being struck by a vehicle on Riverside Drive early this morning. Police have been reminding drivers to slow down this month after a string of collisions involving pedestrians, including some fatal crashes. Ottawa police say road closures are in effect on Earl Armstrong Road and Canyon Walk Drive; and Fairbanks Avenue and Crestview Road. Police are asking motorists to seek alternate routes.