If you're going to live on the flight path to Toronto's Pearson Airport, you could be in for a smelly surprise.

For the second time in a week, a family in Mississauga, Ont., says they've been "poo-bombed" by passing aircraft — although Transport Canada doesn't agree.

"It just covered the top of my mom's car, dripped down the side, splattered onto my car and back onto my dad's," said Lindsay Sullivan describing the damage from above.

The driveway of the Sullivan family home is clean now, but on Wednesday it was covered in something else.

"It smelt really bad," said George Sullivan. "It smelled like it was feces."

The family took photos of what they discovered.

And George Sullivan says he believes he knows the source of the mess.

"There's no way one bird could have done it, unless it was a pterodactyl," he said. "It came from an airplane."

GO bus driver Gary McCourt also shared photos with CBC News of what he says he drove through on Dufferin Street near Highway 407 last week — something McCourt described as a 'brown column' coming down from the sky.

It was just last week that another Mississauga family discovered a mess in their backyard — which is not far from the most recent incident.

Both Mississauga families believe they were bombed by "sky poo" — frozen waste that fell from the side of passing aircraft.

Transport Canada took samples of the first incident and is looking into the second one.

It says airplane washroom reservoirs aren't supposed to open during flight, but leaks can happen.

On Thursday, it concluded "that the debris that fell on the Mississauga residence last week did not fall from an aircraft. Consequently, the investigation is now closed."