"Man Killed by a 1.5 Tonne* Cow After It Crashes Through His Corrugated Iron Roof"

H/t Steve Abbott, from The Daily Mail:
A Brazilian man died after a cow crashed through the roof of his home and landed on top of him as he lay sleeping in his bed.
Joao Maria de Souza, 45, had been in bed with his wife Leni when the animal suddenly fell through the ceiling of their home in Caratinga, south east Brazil. The cow is believed to have escaped from a nearby farm and climbed onto the roof of the couple's house, which backs onto a steep hill.
The corrugated roof immediately gave way and the one-and-a-half-tonne horned bovine fell 8ft onto Mr de Souza's side of the bed. His wife, and the cow, both reportedly escaped unharmed.
Tragic but bizarre - were they not woken by the sound of a 1.5 tonne cow climbing on to the roof? Was it some sort of special stealth cow?
* In case you're wondering what that is in real money, it's 1.4763 imperial tons, i.e. pretty heavy.