In these cases we cry out [even] on the Sabbath: if a city is surrounded by [hostile] gentiles or by a [flooding] river, or if a ship is storm tossed at sea. R' Yose says: [We may call upon the people to assemble] for assistance, but not for supplication. Shimon the Timnite says: Also concerning pestilence; but the Sages did not agree with him.