Drake's Canceled Concert -- Rapper Feared Catwalk Calamity

Drake was worried someone in his audience might get killed ... and that's why he abruptly canceled his Saturday night concert, sources connected with the show tell TMZ.

Drake's people were vague as to why the rapper pulled the plug at the last minute, saying it was due to "unexpected technical issues." Now we can translate -- they were scared the catwalk that loomed over the stage would fall into the crowd.

The catwalk is a big part of the show. Drake walks back and forth on it and there was fear an electrical malfunction could cause a calamity.

The concert arena was filled with fans ... waiting for an hour, when the plug was pulled and they were sent home.

The good news ... the problem is being fixed ... hopefully in time for tonight's show in Montreal. Good that fan safety came first.