VILLAHERMOSA, Mexico (AP) -- One of Mexico's largest rivers rose to
                  the top of a waist-high wall of sandbags Tuesday, threatening to
                  inundate the heart of Villlahermosa, a city of 475,000 people.

                  More water was pouring through a dam upstream, further endangering the
                  22-mile-long temporary dike. A national emergency official said on condition
                  of anonymity that all of Villahermosa, a city 410 miles east of Mexico City,
                  may have to be evacuated.

                  Soldiers and workers from the National Water Commission were doubling
                  and in some places tripling the height of the 4-foot wall of sandbags holding
                  back the bloated Grijalva River, which passes through Villahermosa's
                  commercial district.

                  The river has risen 6 feet in the last three days since authorities opened the
                  floodgates of Las Penitas dam upstream, releasing four times the amount of
                  water normally discharged. The dam was beyond capacity and in danger of
                  breaking.

                  "If this river goes over, it could sweep away half the businesses in the city,"
                  said Noe Ortiz Gonzalez, general director of the local Chamber of
                  Commerce.

                  Silt and trash slowed the flow of water out of the floodgates, but officials,
                  fearful the dam could burst, cleaned the ducts early Tuesday, sending a
                  faster stream of water down toward Villahermosa.

                  It was unclear how much that would raise the river's level downstream.

                 Steady rains over the past month have caused flooding across the region,
                 leaving more than 227,000 people homeless in Tabasco state alone.
                 Local and state officials across southeastern Mexico have reported at
                 least 404 deaths. Many bodies have not been recovered, so the toll could
                 be much higher.

                  Officials warn that if steady rains resume, they may be forced to open the
                  floodgates of three other dams upstream from Villahermosa. Even if that
                  doesn't happen, water levels at Las Penitas still need to drop 5 feet before
                  officials can close the gates.

                  "We could be looking at a major disaster," said Jose Luis Adame, regional
                  manager of the southern border for the National Water Commission.

                  This week's water release pushed water to the rooftops of already-flooded
                  homes and businesses and caused 60,000 people who had stayed behind to
                  flee their homes.

                  On the river, water gurgles out from beneath the wall of sandbags. More
                  than 60 percent of the city's businesses have closed their doors. Dozens of
                  merchants along the riverwalk, the city's prime commercial property, have
                  put their businesses up for sale. Those that remain open have blocked their
                  entrances with knee-high cement walls.

                  "It's hard to sleep at night living next to this. It's very tense," said Raul
                  Ramos, 30, who moved his refrigerator, television and other valuables to the
                  second floor of his home. "I've already seen the wall break twice yesterday,
                  but the soldiers were able to run over and block it in time."

                  Once a tourist attraction, Villahermosa's riverwalk has turned into a silent
                  menace.

                  "Our business has dropped by 80 percent," said Jose Coliente, manager of a
                  home appliances store. "People are afraid the wall might break while they
                  are in here and they'll get trapped."

                    Copyright 1999 The Associated Press.