The bizarre chain of events started when police and paramedics were called to a house on MacIver Blvd. in Newmarket for unknown trouble about 3 p.m.

But as crews were arriving, a woman, who police said had her children, 4 and 7, with her, reversed out of the driveway, crashing into an ambulance, and sped off toward Yonge St.

Police chased the driver, who blew out one of the rear tires on the minivan while reaching speeds of 100 km/h, for about two kilometres down Yonge St. until she stopped at Mulock Dr.

As they walked toward her, the driver put the minivan into reverse and ran into one of the officers, breaking his leg. She put the car back into drive and took off again.

Moments later, she lost control of the 1990 Dodge Caravan, which jumped the curb, clipped a tree and crashed into the front of a house on Yonge St. The car slowed before it crashed, but police said it was lucky the boy and girl, who were not wearing seat belts, weren't injured.

"These kids weren't belted into their seats and if she had hit that tree while she was doing that, those kids would have been rocketed through the front windshield," Staff Sergeant Greg Olson said. "Once the vehicle stops, whatever isn't belted or strapped in becomes a missile, basically. It's just fortunate that she clipped that tree."