A woman is in a coma and a man is in stable condition after a motorboat slammed into the base of a bridge Friday near the Berthierville marina, 75 kilometres northeast of Montreal. Both suffered head injuries.

Two other people aboard were also injured.

"What we know for now is they were following another boat, a bigger boat, which created a wave by passing under the bridge," said S�ret� du Qu�bec Sgt. Gregory Gomez del Prado.

Marina employees called 9-1-1 as they watched the event unfold at 1 p.m.

"It all happened at the marina. The ambulance came, the police, and the coast guard came too," said marina employee Eve-Lyn Ducharmes.

Local residents and witnesses say boaters often don't reduce their speed driving through the bridge, and it can create waves up to three feet high.

"I'm scared all the time. You check everybody. And I check the wind, I check the sea, I check everything," said experienced boater Michel Gauthier. "Maybe there needs to be more security. Everyone should take courses. I think people aren't well informed."