A routine tourist trip turned tragic when the Sinbad submarine sank off Hurghada's coast. The incident resulted in six deaths and nine injuries. Investigations are underway to determine the cause, amid concerns over the vessel's previous safety issues.

At least six people were killed and dozens were injured Thursday after a "recreational" tourist submarine sank in the Red Sea off the sprawling Egyptian beach resort of Hurghada, 280 miles southeast of Cairo.

The Red Sea Governorate said the submarine had 50 people on board, 45 tourists and five crew, Reuters reported. The tourists were of nationalities including Russia, India, Norway and Sweden, Reuters said.