<!DOCTYPE HTML>
<html>
<head>
<script type="application/javascript">

function crash() {
	var target1 = document.getElementById("target1");
	var target2 = document.getElementById("target2");
	var observer1 = new IntersectionObserver(function (entries) {
	  console.log(entries);
	  observer1.disconnect();
	  observer2.disconnect();
	});
	var observer2 = new IntersectionObserver(function (entries) {
	  console.log(entries); 
	});
	observer1.observe(target1);
	observer2.observe(target2);
}

</script>
</head>
<body onload="crash()">
	<div id="target1" style="background: red; width: 50px; height: 50px"></div>
	<div id="target2" style="background: green; width: 50px; height: 50px"></div>
</body>
</html>
