GARY, Ind. (AP) _ Mayor Richard G. Hatcher on Tuesday blasted a county coroner who called the city negligent in the drowning deaths of five children in a closed municipal swimming pool, but said the city was investigating why rainwater had not been drained from the pool.

The children, aged 6 to 13 and all related, drowned in the algae-covered water of the Fisher Park pool Sunday after they lost their footing on the slimy bottom and could not climb to safety, authorities said.

Lake County Coroner Dr. Daniel D. Thomas has said the city was negligent for failing to pump out about 5 feet of water left in the pool's deep end.

''It was unfortunate and misinformed for the Lake County coroner to make statements that he had no factual basis for making,'' Hatcher said at a news conference.

''I believe the question of negligence is a legal matter that has to be determined in the courts,'' he said later. ''I don't believe a coroner is a judge or a jury.''

On Monday, city parks Superintendent Edward Chalko said the city routinely left standing water in closed pools to keep the bottom from buckling.

Chalko and Hatcher on Tuesday backed away from that assertion and said a city investigation had begun to determine why the children entered the pool and why the water had not been drained.

''Until that investigation is complete, obviously it will be difficult to speak with authority regarding those matters,'' Hatcher said.

Police said the children had sneaked into the pool to catch frogs. City pools were scheduled to open June 24, about two weeks after public schools closed for the summer.

Hatcher said the pool gates were padlocked and that the children either climbed over or sneaked under a barbed wire-topped, six-foot fence. In 1978, two children drowned in the same pool while searching for tadpoles.

Some neighborhood residents reacted angrily when Hatcher visited the pool Monday and refused to make a statement.

The mayor said Tuesday that he sympathized with the residents' emotional responses to the deaths but refused to respond to their criticism.